Refine SHA-1 related stuffs.

1. Introduce libbcc.sha1.so instead of raw file libbcc.so.sha1
    * Now tools/build/gen-sha1-stamp.py generated assembly contains
      symbols libbcc_so_SHA1 and libRS_so_SHA1 associated with their
      SHA-1 digests.
    * In that way, their SHA-1 information can be obtained via
      dlopen().
2. Refine Sha1Helper to Sha1Util.
2. Remove unused tools/build/dataconvert.py by the way.
13 files changed