Added getPointerToNamedFunction implementation to ZMemoryManager.

Constraints:
1) we have to mount ELF nexe as channel to be able to read it
2) using thirdparty elfio library (MIT license)
3) can resolve only 'already-linked in' symbols
Tests added for ZMemoryManager getPointerToNamedFunction implementation.
Revert "Added getPointerToNamedFunction implementation to
ZMemoryManager."

This reverts commit e268764479e780a3da2d2c853c6718aea05c9bec.
Executon engine creation succesfullty calls LoadLibraryPermanently.

With libzdl instead of libdl. Tests modified.
configure prefix is set to ZVM_PREFIX
Merge branch 'github/dlsym'