Change --show-exc to --show-stderr
Only show stderr when requested.
Allow importing shared code within the benchmark tree.
Fix UnboundLocalError
Python 2.6 compatibility
Merge pull request #128 from mdboom/show-stderr

Change --show-exc to --show-stderr
Merge pull request #130 from mdboom/import-as-package

Allow importing shared code within the benchmark tree
Merge branch 'master' of https://github.com/spacetelescope/asv into dumb

Conflicts:
	asv/commands/run.py