add contributing document
Merge pull request #33 from tsloughter/next

add contributing document
Merge remote-tracking branch 'erlware/next'
bugfix for empty configs in the Erlang API
move discovered releases to their own area of the relcool state
support shared resoure as far as discovery goes

also correctly handles symlinks without infinite loops
fix bug in rebuild rule of makefile
fix bug in release override test suite
Merge pull request #34 from ericbmerritt/next

various bug fixes to symlinks.
Merge pull request #36 from erlware/next

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