Change "Dream World" to "hidden" abilities

- Removed dreamWorldRelease and added unreleasedHidden
- Replaced maleOnlyDreamWorld with maleOnlyHidden
- Replace 'DW' ability with 'H' ability
- Changed isDW variable to isHidden
Correcting grammar in HP’s description
Merge pull request #400 from ALAKTORN/patch-6

Correcting grammar in HP’s description
Remove isDW from Gen 4 events

Also moved CAP to the bottom to match Gen 5/6
Merge remote-tracking branch 'upstream/master'