This allows plist objects to be accessed directly from cexpr expressions
using struct.field syntax for dictionary objects and array[index] syntax
for array objects.
The problem is that I needed to support dynamic types on operators (for
bit-field enums), had things working, but a bad edit messed things up
and I had to rebuild that bit of code. Missed one bit :P
It is capable of parsing single expressions with fairly simple
operations. It current supports ints, enums, cvars and (external) data
structs. It is also thread-safe (in theory, needs proper testing) and
the memory it uses can be mass-freed.