Parse splat operators in method calls.

Signed-off-by: Yorick Peterse <yorickpeterse@gmail.com>
Parsing of empty strings.

Signed-off-by: Yorick Peterse <yorickpeterse@gmail.com>
Parsing of dvar embedded expressions.

Signed-off-by: Yorick Peterse <yorickpeterse@gmail.com>