-Idle tick is now responsible for dispatching all pending sound sources, as such improves priority sorting.
-Added ui sound precache mechanisms (to fetch sounds without associated soundsources)
-Audio engine no logner available pre-login or upon disconnect, for simplicity.
-General cleanup to the audio engine/impl.
-Fixed some gAudiop calls that were lacking prerequisite null checks.
-Added 'isUpstreamOK' procuedure to LLAssetStorage to allow avoidance of making requests when there is no upstream host connection.
-Added ui-local transformation matrix.
-Gutted legacy commitcallbacks throughout ui widget ctors.
-Created filter_editor ui widget which issues commit on keypress
-search_editor commits on focus loss/enter press
-search_editor and filter_editor now have a built in 'x' button to clear text.
-LLComboBox::setPrearrangeCallback now uses boost::function
-LLComboBox::setTextEntryCallback now uses boost::function
-LLLineEditor::setKeystrokeCallback now uses boost::function
-LLLineEditor::setPrevalidate now uses boost::function
-LLPanel::childSetKeystrokeCallback removed
-LLPanel::childSetPrevalidate removed
-LLPanel::childSetActionTextbox now uses boost::function
-LLTextBox::setClickedCallback now uses boost::function
-LLTextEditor::setKeystrokeCallback added.
-Cleaned up JCFloaterAreaSearch
Call AIFilePicker::create() instead of new AIFilePicker.
Renamed deleteMe() to kill() and bs_deleted to bs_killed.
Only default to auto destruct when created with create(true),
otherwise kill() has to be called explicitely.
Also upgrade the file picker filters with the new extensions found
in the orginal file picker code of Singularity.
Also improve AIFilePicker a bit: added hasFilename() and now
deleting the statemachine automatically by default: it's no longer
needed to call deleteMe from the callback.
