Perform shell expansion when loading sbtopts files.

This is so that tilde and variable expansion gets performed before
the sbt command line is built, otherwise options like "-ivy ~/.ivy2"
don't work, because the tilde is never expanded.
Migrate universal windows scripts into universal directory.

ALso, added back the commented sbtopts settings.
Fix config file loading to do shell expansion first.

from @benevans.
Merge pull request #46 from benevans/shell-expansion

Perform shell expansion when loading sbtopts files.
Merge remote-tracking branch 'origin/full-packaging' into wip/windows-jansi-fixes