DEV-19836 Add --package and --viewer-only options to develop.py.  Ported from maint-viewer.  OK by CG.
DEV-19836 Add --package and --viewer-only options to develop.py.  Ported from maint-viewer.  OK by CG.

Merging revisions 95145-95146,95281-95282 of svn+ssh://svn.lindenlab.com/svn/linden/branches/maint-viewer/maint-viewer-10 into E:\release, respecting ancestry

gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm,gabeharms/firestorm