STORM-987 : Add the --image-stats argument, make argument passing more consistent, fix typos in comments in llimage header

STORM-987 : Add --logmetrics and --analyzeperformance arguments, moved analyzeMetricPerformanceLog() and doAnalysisMetrics() from LLFastTimerView to LLMetricPerformanceTesterBasic

STORM-1014: Viewer crash in LLSurface::getWaterHeight
STORM-1047:[crashhunters] crash at LLViewerObjectList::renderObjectsForMap

STORM-1014: Viewer crash in LLSurface::getWaterHeight
STORM-1047:[crashhunters] crash at LLViewerObjectList::renderObjectsForMap

ER-350:  Viewer / sim camera positioning not working well on login.  Viewer now sets the camera before calling send_agent_update().  Reviewed by Kelly.

reviewed by davep

reviewed by davep

Fixed:
* Wrong ability to place a button between the chat input and the drag handle (thanks Wolfpup!).
* Broken drag-n-drop cursors.

- To decrease code duplication:
  * Added RS_BUTTON_SPEAK to the button->panel mapping (mStateProcessedObjectMap).
  * Replaces all lookups in mStateProcessedObjectMap with calls to getButtonPanel().
- Added some comments.

Cumulative diff of changes made by Wolfpup, Richard and me.

Description:
* Ability to hide the Speak button with the bottom tray context menu.
* Made the chat input resize handle visible, so that the feature is easily discoverable.
* Applied Richard's fix to layout panel resizing logic.