Add support for bytea objects.

Conflicts:
	src/python.c
Fix error recovery on user mapping.
Merge branch 'master' into writable_fdw
Fix insert and delete for fsfdw.
Add errorcheck
Merge branch 'master' into writable_fdw
Fix gitignore
Add a python instance cache invalidation mechanism.

Before this, a cached FDW instance would be kept until the death of the backend.
This patch caches a list of options and a list of column definitions to be
compared against the current set of columns / options of the foreign table. If
they don't match, the cached instance will be replaced by a fresh instance using
the new values. Fix #11.
Fix the test case when adding a column.
Merge branch 'master' into writable_fdw

Conflicts:
	src/python.c
pgindent.
Merge branch 'master' into writable_fdw
MacOS X installation patches

fixed sed -i issues on OSX
fixed hardcoded /usr/include/{postgresql,python} directories in
Makefile and setup.py
adjusted .gitignore
Remove empty "strings" from modified sed line.
Merge remote-tracking branch 'upstream/master'
Fix order of sed arguments so it works on both mac and ubuntu.
Allocate cached options and columns definitions in another context.
Merge pull request #12 from davidcrawford/fix-mac-make

Fix make install on Mac OS X
Remove duplicate lines for ignoring "*.o".
Merge branch 'master' into writable_fdw