Rework Theme Developer so it use a file based cache for the variables. This avoids max_packet_size error on mysql.

#267204 by ksenzee. fix some render problems in theme developer by emitting span around page using js instead of php.

Theme developer now has its variables back and all is fast and memory efficient. For those that choose to move their krumo subdir out of the way or otherwise disable krumo(), there is a bug in devel_print_object() where it seems not to handle recursion properly and even without recurssion, the popup does not properly expand its output when clicked.

First half of rework of Theme Developer to be faster and less memory intensive. Instead of sending all the variables for all theme calls in each request, we save the variables to a cache table on the server. In the next commit, the popup will retrieve the variables on demand if the user cares to view them. The menu callback for this AJAX request is done - just need javascript work now.

revert list of candidate function to a simple list, instead of a theme item list. that was confusing. jeff is right.

defend against theme functions that return arrays or objects. see theme_table_select_header_cell. bad function. bad.

simplify how we collect template suggestions. flip the order of candidates to most specific first, and fix template log. also add more candidates for functions.