tools/pipbot: Add 'checkout' command

Issue #188.
Add a Markdown log file

... and copy over the first 3 days of notes.

Issue #191.
log: Small style fixups
log: Import generated Markdown

Issue #191.
log: Some formatting to Markdown log

Issue #191.
log: Markdown formatting

Issue #191.
tools/pipbot: Refactor show() error path

Issue #204.
tools/pipbot: Print usage if 'show' arg is unkown

Issue #204.
tools/pipbot: Refactor for get_configure_args()

Issue #204.
tools/pipbot: Add the ability to show configure args

If pipbot is invoked with 'show <target> <build>' arguments, then the
output is the list of configure arguments for that configuration. Eg:

$ ./pipbot show local debug
./configure \
        --disable-minify-css \
        --disable-minify-html \
        --disable-minify-js \
        --enable-content-hashing \
        --enable-debug \
        --enable-documentation \
        --enable-git-hooks \
	--enable-tools \
	--enable-install \
	--disable-authentication \
	DB_HOST='localhost' \
	DB_NAME='pipdb' \
	DB_PASSWORD='mypassword' \
	DB_USERNAME='username' \
	WWW_ROOT='/var/www'

Issue #204.
Merge branch 'feature/204'
Merge branch 'feature/191'
scripts/git: Remove pre-commit doctoc for project log

Issue #204.
Documentation: Move log.md out of log/ subdir

Issue #204.
Documentation/README.md: Update reference to log

Issue #204.
build/Documentation: Add log to EXTRA_DIST

Issue #204.
Documentation: Remove log/ subdirectory

Issue #204.
configure: Don't generate Documentation/log/Makefile

Issue #204.
build: Pipe stderr of 'find' to /dev/null

Issue #192.
build/www/lib/Twig: Remove CLEANFILES

This is covered by the CLEANFILES variable in build/Makefile.am.

Issue #192.