Nested function call inside commands do not return values

[Chimaine]

If a function call is nested in an argument for a command (like say), the parser does not recognize it correctly and the call is said to return no value.

[Chimaine]

say "Bar" ToString( $foo ); // This code fails with an engine error.

[Chimaine]

Revamped jumps, new direct parser, no special expression form for command expressions. Fixes #5

→ <<cset 170db3b7d36a>>