added support for launching ipdb on exception
Merge pull request #127 from ahmadia/ipdb_debug

added support for launching ipdb on exception
updated docs slightly
Merge pull request #130 from ahmadia/tutorial-fixes

updated docs slightly
Fix a typo
Merge pull request #133 from certik/typos

Fix a typo
FTP protocol is supported, remove the check

The FTP protocol has always been working for me, and
some packages like GMP require it.
Merge pull request #134 from certik/ftp

FTP protocol is supported, remove the check
Use correct shebang
Shebang: look for artifact.json

Instead of profile.json
Merge pull request #136 from hashdist/shebang

Fixes shebang
Update a test to look for artifact.json

Instead of profile.json
Update the test for shebang

The test was testing the old behavior when shebang is not updated. Since we
update it now, we need to modify the test to expect this new behavior.
Merge pull request #138 from hashdist/fix137

Fix137
Expose keep_build to the command line

This allows the user to specify the keep_build argument, thus whether the build
directory should be always kept, never kept (currently the default) or only
kept on error.
Update tests for the new keep_build argument

The build() method does not have any default arguments, so we continue in this
convention and simply require all code (including tests) to explicitly specify
keep_build.
Merge pull request #139 from hashdist/keep_build

Expose keep_build to the command line
Merge remote-tracking branch 'origin/master' into debug

This resolves @certik's keep_build flag into the debug branch.

This also unifies the calling parameters for builder.build as mandatory.

Conflicts:
	hashdist/cli/frontend_cli.py
	hashdist/spec/builder.py