Remove obsolete unsets from install and selfupdate scripts.
Improvement on platform specific hacks for cygwin.
Fix problem switching from local version to standard.

In isolated mode, attempting to switch from a locally installed version to a
standard one would fail if the label for the local version did not start with
a number, e.g. 'dev'. One of the regular expressions in gvm-use.sh was still
assuming that versions always began with a number, which of course is no longer
the case.

I fixed the regular expression and added a corresponding Cucumber scenario.
Bug fix on defaulting candidates after installation.
Add list functionality for local candidate versions.
Remove separator in list template.
Updates to README to explain running GVM server locally.
Tweak README markdown.
Upgrade version to 0.9.5, add mongo release script.
Tweak install function for zsh compatibility.