RFC-3: Change data and libs segment requirements

[dr-orlovsky]

In order to allow better AluVM support & operations on low-memory hardware devices the following changes are proposed:

1. The data segment maximum length should be decreased to 2^16 (the same as code segment). If program needs more data, it should use special "data libraries".
2. The maximum number of used libraries per single library must be decreased to 256.
3. A new limit of "total libraries" is introduced and this amount should not exceed 1024.

This will allow to limit the size of a single library to just 136 kB (139520 bytes) and provide a restriction on total size of any program (some library + all of its tree descendant dependencies) at 136 MB, with the ability of having up to 64 MB of data.