fixed import of TextClient class in gtkPanes module

The TextClient class have been moved to text module.

Now it should be possible to run 'buildbot statusgui' again.
Fixed IRC bot reacting on unclosed single quote.
IRC bot notify about command with unclosed quotes.
Repeated code was replaced.
Merge branch 'fix-statusgui-import' of git://github.com/elmirjagudin/buildbot
don't run coverage in validate.sh

It's really slow, and Buildbot runs it anyway.
fix: Correct DebCowbuilder handling for existing images

In pull request #482 introducing the DebCowbuilder class, there is a
wrong assumption being made on the type of the file system entry holding
the chroot. While it is correct for the base pbuilder case that this
entry have to be a file, the cowbuilder case handles directories. But
the base class used by DebCowbuilder only checks for regular file.
Hence, it triggers an error in twistd.log and makes the step failing
after a first run.
Correct deferred handling in status_push.py

Fixes #2450.
Added few tests.
Removing redundant code.
Function name changed
Merge branch '631-shlex-singlequote-issue' of git://github.com/MichaelMayorov/buildbot
use Python-2.5-compatible syntax
Merge branch 'fix-cowbuilder' of git://github.com/lissyx/buildbot
Add explicit instructions to install sqlalchemy==0.7.10, since 0.8.x doesn't work