Renamed panels_get_directories() to panels_get_include_directories() to be more precise and descriptive.

Removed the pretty unhelpful panels_content grouping.
Fixed the docblock for panels_context_get_keywords() that was borking doxygen and causing nothing after it to be documented.
Updated the mainapi api docs grouping as needed.
Added the HookInvocations api docs grouping as appropriate.

Critical fix to plugin handling: client modules adding certain plugin types via the panels_include_directory() method were only half functioning.

Due to a foolish way of handling the module name in the first-round implementation of panels_include_directory(), module name information was not being properly recorded in plugins that needed it (layout plugins, esp.). The method of handling module name strings has been changed to resolve this problem.

#268480 by smk-ka: Fix to make sure that cached panes still get acted on by hook_panels_pane_content_alter().

#256461: Allow individual panel pane styles. This requires a small modification to existing panel styles so that panel styles don't conflict with pane styles, but it is very minor, and very few panel styles are out there yet.

Updated three content_type plugin properties: "ignore roles" is now "role-based access"; expanded the variables passed to "form control" and "visibility submit" callbacks.

#260221 by sun, Pancho. Primarily codestyle cleanup; also fixed some missing leading slashes that were causing the edit icons not to appear in the new helptext for the display editor.

Changed show/hide settings to be more in line with the rest of the access control parameters. Part and parcel of that was moving storage of the pane show/hide information into the pane table itself...probably where it should have been from the start.

panels_pane_access() is now the primary handler for the overall panels pane access logic. Depending on settings in the $display object and the content_type of the pane being checked, panels_pane_access() now  may or may not check $display->pane->access, any visibility check callbacks defined by the content type, and can use (what amounts to, but is not exactly) AND or OR logic in evaluating these.

BIG CAHUNA: scrapped functions from split add/edit pane config workflow in the switch over to a unified approach. Added some more default values to content_type array definitions to ease E_STRICT warnings and facilitate other parts of the process.

Reworked panels_plugin_get_function() so that a) it accepts arrays as well as objects containing ct config information (they're usually in array form, anyway), b) uses a var name for the content_type object that's more explicit than '$object', and c) added an isset() check prior to function_exists() to avoid E_STRICT warnings.

minor updates to fix typos in some doxy documentation; added an isset() to circumvent some E_STRICT errors; renamed several variables in various major API engine functions both for consistency and so that the variable names better reflect their contents.

panels_ct_get_types() had a relic $conf variable still hanging around in it, the inclusion of which was causing numerous E_STRICT errors. Removed the superfluous $conf.

updated panels_get_directories() doxy to be a little more specific. Doing so also made clear the need to add more documentation to the .inc files, as well as adding some @see information to the panels_get_directories() doxy once that documentation is complete.

rolled back changes on array_key_exists(), as the one circumstance where it differs from isset is actually potentially likely to occur, whereas the case where array_key_exists() should only occur as a fluke

bringing panels_include_directories() hook invocation documentation into line with drupal coding standards

switched array_key_exists() over to isset; has the exact same effect, but handles unexpected data (i.e., non-arrays) without error

removed extraneous call to panels_load_hooks(); as far as I can tell, the call is now COMPLETELY deprecated and does nothing except waste a call to module_implements()

#233588 - updated hook_panels_include_directory() so that it does its job and has some protection against bad values being passed in

#233588: (by sdboyer) Allows external modules to tell inform panels of additional locations to search for panels plugin *.inc files.

Fix from recent commit that broke required contexts in arrays, which broke panel views as well as mini panels

Fix for contexts so that arguments that fail to locate a context don't provide some false unusable context when they should be filtered out

#200808: Alternate displays from arguments were totally broken by commits designed to make default panels not need to be overridden so often.

Administrative looks and a hook_panels_pane_content_alter so modules can muck with pretty much anything on pane output.