gignore: remove illegal components (issue92)

mercurial can't ignore .hg direcotry.

--HG--
extra : rebase_source : 580dc986831dd4580ac5cc74a02708307ea5204a
Makefile: drop support for hg older than 2.8.2

Ubuntu's current LTS release (Trusty Tahr) comes with Mercurial 2.8.2,
which still works fine with current code. The older LTS comes with a
version that's broken, but I don't have to worry about that anymore.
setup: bump version number, correct author
Added tag 0.6.0 for changeset 9f20b66027c2
Added signature for changeset 29f51877a610