Rename to FetchBuilder.
Rename --builder-arg to just --arg in build command.
MANIFEST.in: include README.mkd and asciidoc files

When `python setup.py sdist` is run to generate a source tarball for
`rpmbuild`, it currently doesn't include some key files which causes
`rpmbuild` to fail. So add these to `MANIFEST.in`.
More testing.
Add support for passing builder args through a releaser.
Support release with fetch builder.
Fix releasers and respect offline flag.
Add some documentation for FetchBuilder.
Add markdown docs for FetchBuilder instead of manpage.
Markdown fixes.
Assume a default fetch strategy.
Add a missing rpm macro to fetch builder.
Fix a problem with spec file.

Newline was causing a problem somehow, not sure what this one was.
Fix bug with fetch builder source replacement.
Merge branch 'add-asciidoc-to-sdist' of https://github.com/grosskur/tito into grosskur-add-asciidoc-to-sdist
Add more missing documentation to MANIFEST.in.
Add GitAnnexBuilder, using git-annex to store blobs

This is an extension of NoTgzBuilder, which instead of storing blobs in source
control directly, allows the use of git-annex to reference blobs in an external
source (e.g. a web URL remote).  When preparing sources, it uses git-annex's
unlock command to temporarily restore the original file.