Minor grammar fix.

Fixed a grocer's apostrophe in the Readme.
Use Clang and GCC on Travis
Add support for Source Map Revision 3.

The parser has been adjusted to keep track of the current position
(line and column) instead of the current line. The position to the start
of the token an AST node is generated from, is stored in the node. During
code generation we keep track of the current position in the target file.
For each node of interest we create a mapping between the position in the
source and target file. Finally, a source map following the Source Map
Revision 3 specification can be generated for the collected mappings.
Merge pull request #207 from svnieuw/sourcemaps

Add support for Source Map Revision 3.
dont run todo with basic test line
only run the build tests on travis
Add test stuff into Makefile.am
Forgot to add these tasks
Merge pull request #209 from jbussdieker/master

Add test stuff into Makefile.am
Fix dependency
Remove unnecessary target
Fix travis.sh script
Merge pull request #210 from jbussdieker/master

Fix dependency
Update Readme.md
Update Readme.md
Merge pull request #206 from nschonni/patch-1

Use Clang and GCC on Travis
merge!
Merge branch 'master' of github.com:hcatlin/libsass
Add pkgconfig support
Remove some autotools artifacts that I should never have commited