Bump version to 2.1.0

Properly express dependencies toward Pitest

Because:
 - We were still depending on Pitest 1.4.6 even though we actually ship Pitest 1.4.11
 - Was causing troubling during deployment

How:
 - Update MANIFEST.MF files
 - Remove features' version from category.xml

Bump version to 2.0.1

Bump Tycho version to 1.5.0-SNAPSHOT

Because:
 - Tycho 1.4.0 does not handle additional repositories in p2.
   I use them to specify that Guava can be automatically
   downloaded from Orbit if the user does not have it installed.