Adding the ability to ignore sessions when setting messages in the Template library. Mainly useful during unit tests.
Activity model tests.
#808 Template library optimizations

Cut the number of calls to find_files() nearly in half for most pages on
my site and improved the performance of find_files() itself slightly
(some sites with unusual configurations, i.e. multiple theme paths, may
see a more significant improvement)
Initial user tests. Still needs many more but this is boring tonight.
Added the Lex Parser engine to work with the Template library.
New parser now works properly with views in themes.
Updated installer to check for minimum PHP 5.3
Reverting template lib to latest branch changes. Will merge the parser code next.
Bringing back in the new parser changes to the template file.
Add configurable settings to Site Settings

extended_settings config file uses similar syntax to user_meta to
configure an "Extended Settings" tab on the Site Settings page. Config
file sets what settings are included on this tab as well as permissions
required to view them, the valid values, and the controls used to render
them.

The extended settings are saved to the existing settings table in the
database.

If the 'extended_settings_fields' config array is empty, the tab is not
displayed on the Site Settings page.

This is a re-submit and fixes the merge issues on #756. This implements
the "Planned" item from the roadmap: https://trello.com/c/SADM7rd3
Updated CSSMin, Fixed Assets::js() 1st argument, Added $prepend to Assets::add_css(), Removed $type argument from Assets::generate_file()

- Assets::js() was handling first argument by casting it to a string and
passing it to external_js() if it was not empty, even when it was an
array, without regard to the $type argument
- Added $prepend argument to Assets::add_css() to control whether CSS
assets are added to the beginning or end of the array, makes it more
consistent with add_js(), which may be useful later...
- Removed $type argument from Assets::generate_file(), which was unused
and confusing, since $file_type already handles the type
- Updated CSSMin to 3.0.1
Fix #812 can't drop 'temp_password_hash'
Update user_model for compatibility with MY_Model changes in e77ea0aa9be4f48cf38cd2c5f5d81e52b15429a1

Additionally:
- cleaned up PHPDoc comments in MY_Model.php
- removed unused $return_type argument from BF_Model::find() method
- refactored BF_Model::delete() and BF_Model::delete_where() to show the
similarity in their logic (should probably make one a wrapper of the
other)
- added @internal note to BF_Model::count_all() regarding potential
confusion with $this->db->count_all()