db_manager: do not display index tables when browsing SpatiaLite databases
Do not assume mScheme is not null

Fixes crashes with ENABLE_MODELTEST set at build time on opening
options editor
Merge pull request #1705 from marcel-dancak/db_manager-spatialite-index-tables

db_manager: do not display index tables when browsing SpatiaLite databases
Fix #11928 - import os for las tools
Fix panning from overview map with non-zero rotation

Closes http://hub.qgis.org/issues/11816
Fix cppcheck reports:
[src/providers/ogr/qgsogrprovider.cpp:1071]: (error) Memory leak: oldlocale
[src/providers/ogr/qgsogrprovider.cpp:1268]: (error) Memory leak: oldlocale
[src/core/spatialite/spatialite.c:50598]: (error) Memory leak: reader
[tests/src/core/testqgscolorscheme.cpp:155]: (error) Memory leak: dummyScheme2
[src/core/spatialite/spatialite.c:40138]: (error) Memory leak: ln
indentation update
make canvas rotation support available in options
fix warnings