added ignore for dbghelp.dll

reviewed by James

EXT-1402 - Thousands of "WARNING: LLAssetStorage::getAssetData: Discarding duplicate request for asset" lines
Added a list of requested landmark assets and limited the frequency of multiple requests for the same asset

fixed reflow logic when resizing text editors that contain widgets (would make text appear and disappear)

reviewed by James

* Still need to only request smaller mip maps of icon textures

to be reviewed by davep

Changed mTabs to hold LLSideTrayTab* so we don't have to dynamic_cast<> everywhere
Reviewed with Leyla.

Main change is pointing install.xml for Windows to new version of LLQtWebKit that has DLLs with no manifest as per recent build change.
Tweaked bookamrks for test app too.
Finally, added fix for DEV-41392 (Home URL Preview should be next to the Home URL)

DEV-41787 Media Auto Play controls were removed from prefs.  Also made auto play override prim settings.

Two part fix: prevented the copying of wearable parameters to the avatar to trigger a rebake.
Then: Called wearableUpdated every time a wearable was added/removed/replaced and ensured it properly invalidated the composite

Confirmed working fix on developer machine.

Code reviewed by Seraph.

Changes to match new version of llqtwebkit -- passing modifier keys through to most user events and using new scroll wheel event.

For EXT-1863 : "Wear" and "Take Off" for items should be properly greyed out depending on item worn state

Merging revisions 2156-2183 of https://svn.aws.productengine.com/secondlife/pe/stable-2 into P:\svn\viewer-2.0.0-3, respecting ancestry
* Bugs: EXT-1590 EXT-1694 EXT-1660 EXT-1646 EXT-1694 EXT-1316 EXT-1775 EXT-1798 EXT-1799 EXT-1117 EXT-1571 EXT-1572
* Dev: EXT-1757 EXT-991 EXT-1758 EXT-1770 EXT-1192 EXT-1613 EXT-1611 EXT-1256 EXT-1758 EXT-747

svn merge -r137024:137071 svn+ssh://svn.lindenlab.com/svn/linden/branches/avatar-pipeline/avatar-pipeline-14-seraph into svn+ssh://svn.lindenlab.com/svn/linden/branches/viewer/viewer-2.0.0-3
Bugs: EXT-1785 EXT-1818 EXT-1820 EXT-1845

These textures are used during terrain rendering.  Not having them also
breaks invisiprims in an interesting way.

for testing purposes.