FEAT: added string! TO number! action.

FEAT: code refactoring for %dtoa.reds.
FIX: added an tailing char for trans-float.
FIX: redefine sin/cos in Red/System tests.
FIX: issue #853 (/extern misbehaving in interpreter)
Merge branch 'master' of github.com:red/red
FEAT: granted wish #851 (Add a new keyword AFTER to PARSE)
TESTS: added AFTER tests.
Merge branch 'qtxie_red/float-datatype'

Conflicts:
	runtime/datatypes/float.reds
	runtime/datatypes/integer.reds
	runtime/datatypes/string.reds
Merge branch 'origin/master'
Merge branch 'origin/master'