Bump peas version to 1.5
Set gedit gir dir using gedit prefix
Added XML backend. Only deals with parse errors at this point.
Added support for parsing RelaxNG files and validating XML against RelaxNG files when they are referenced with a modeline.
Added support for parsing XSD files.
Move comment parsing for a schema to a more efficient function.

Removed generic excaption catch since it might not be meaningfull
to the user without pointing them to a line number.
Set working directory for make to makefile directory
INSTALL is autogenerated
Use AM_VALAFLAGS
Fix build
Add clang include depending on the version
Fix some warnings about Sequence static functions
Revert previous commit as it seems to crash.
Improved clang not found in configure status
Export llvm version in main config

This avoids distcheck problems when configure would generate a vala
file newer then the timestamp (which would cause an attempted rebuild
of c files from vala files, which in case would make distcheck fail).
Do not try to clean the vala time stamp
Release 0.1.4
xml: the sources are python
Release 0.1.5
Port to python 3