Install the given gem file instead of alternates

When multiple versions of the same gem exist in the same directory only
the gem given by file name should be installed.  This restores this
functionality.

Fixes #875
Add #834 to History

This was probably fixed by #875
Sort list of possible gems to unistall

When the user has multiple gems to unistall RubyGems asks which gem you
want to uninstall.  This list was not sorted so the order may change
from run to run.

Now the list is sorted.

Fixes #918
Only update gems names that match exactly

Previously RubyGems used a regular expression to match gem names for
updating but this makes little sense.  Now RubyGems uses exact matches
when updating gem names.

Fixes #919
Add #919 to History

commit miss
Debug commit for travis failures
Sort list, not names of gems for #918

Sorting the list of names gives incorrect results as the order of the
gems in the displayed list and the order of the gems are not the same.

By sorting the list everything will work again.
Add #916 to History

I think removal of development dependencies fixed this bug too