Remove some unused classes from the v8 API

Change-Id: I6fdb7903a3cdb3b3167144f78bd7cf58647deb67
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
Get rid of v8::Integer

Change-Id: I6b9ab830c4ff3cbf986dbcf7c056648b5a16a222
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
Get rid of v8::Number

Change-Id: I38bdf8fe4dd73c61317912ec6308a9a1e870ad99
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
Get rid of v8::Boolean

Change-Id: I10b4240db78532dfdf972bb0a6f191462d81caaa
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
Get rid of v8::Primitive

Change-Id: Idd31a8d522119cade9bb18854e124b80f1c57123
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>