Proposal: make it standalone

[EgorkaZ]

There are several versions of clang being used around there, with corresponding libclang versions. Libclang is not backward compatible, thus, migration to a new version would either force to support ICA on both versions or to abandon older clang support

Making it standalone (ideally, statically-linked) executable would give much more freedom for developers to base on any libclang version they want and for users to not maintain their clang and ica versions synced