[cleanup] Make arrays statically sized

Size runtime-sized arrays are nonstandard we should
avoid them. Here we use the same upper estimated
that was already used in the local() methods.
[cleanup] Avoid signed/unsigned comparison
[cleanup] Avoid signed/unsigned comparison
[ceanup] Use td::vector instead of runtime-sized array
[capabilities] Deprecate isParallel capability

Deprecation of isParallel was decided on the 2014 developer
meeting for the 2.4 release.