Dynamic variable allocation

[x87]

idea mentioned there thelink2012/gta3sc#117
needs a design.

[thelink2012]

My idea was primarily based on creating some pluggable way to extend the CRunningScript structure (#14), and then CLEO itself could make use of this interface to allocate more variables.

A custom header would be added to the script file indicating that it wishes to use the dynamic variable system, This header would inform the scripting system how many variables should be allocated as well This way, we don't need to keep things on the TLS array. All scripts wishing to use more variables would basically be accepting the contract of not relying on the TLS array offset, and instead using the GET_VAR_POINTER command.

Some prototype of the pluggable system is on some branch at some fork of mine. It's no more than a prototype, given its use of slow data structures for the task. See #14.