Implement input plugin for PostGIS Rasters

Closes #1660.
Includes python bindings and testcases.
Add optional extent paramater to ogr plugin
travis: only test with clang
multiface font tests
font_registration test: only modify severity temporarily
fix support for ttc/dfont font formats

  - both formats likely will contain multiple valid faces
  - ttc should work on across platforms - dfont is likely osx only
  - fixes #2274 and 2341

Thanks @strk for helping uncover the problem and providing a testcase
OGR plugin extent test
formatting
formatting
formatting
Undo stupid windows file permissions change on rundemo.py
Merge pull request #2350 from kernelsanders/2.3.x

Add optional extent parameter to OGR datasource plugin
deprecate bilinear8 in 2.3.x - refs #2076
rollback png8 default in 2.3.x - closes #2110
ogr plugin extent error handling
Merge pull request #2329 from strk/2.3.x-pgraster2

Implement input plugin for PostGIS Rasters
travis: create and init template_postgis
travis: see if postgis works with default postgres
travis: try without ubuntugis-unstable
travis: try by declaring libgdal1h=1.10.0-1~precise1