#350408 by pillarsdotnet: Selecting "Regenerate marker cache" does not reliably clear and rebuild the marker cache.
Changes:
gmap_regenerate_markers()

    * Pass TRUE to the gmap_get_icondata() function
    * Pass TRUE to the gmap_set_marker_titles() function

gmap_set_marker_titles()

    * Simplify and correct the caching logic

gmap_flush_caches()

    * Add an implementation of hook_flush_caches to ensure that clicking on the "Clear cached data" button from the /admin/settings/performance page also rebuilds the marker cache.

Add shape clickability.

#330343, reported by fabio84 and also by epimeth in irc: Make script url valid again, I forgot that url() returns raw ampersands.

Let people pass map arrays to theme('gmap') without wrapping them in array('#settings' => ...). In theory.

* Remove references to mousewheel.js, clean up variable.
* Add support for Continuous Zoom, enabled by default.
* Add behavior flag for disabling Continuous Zoom.
* Remove workaround from may 2007 (rev 1.1.2.15) that was causing zooming problems.

* Add style keyword to the macro layer.
* Add code to merge styles in properly.
* Allow using references to styles in lines / polys.

Add 'hl' parameter to allow the map to translate itself. (Part of #314777.)

Remove the markerdata hack.
Add a marker file generator and fix markers once and for all.
Add a button to the settings page to regenerate the marker cache.

Fixing align brokenness noted in comment 66 of #266595. I was treating a string as an array and accidentally stomping some css classes.

Make a slight change to how gmap element processing works. This should reduce warnings.
Add some tests.

Since I keep making the mistake of using comma delimited behaviors in macros, we might as well support the syntax.

This change is from #234344.