[0.2.2] Properly load blobs from boot images with prepended data

[0.2.1] Handle HTC boot images with prepended signature

[0.2.0] Rewrite the whole library

* Rewrite libbootimg to use "blobs" concept - kernel, initrd,
  second stage and DTB are all objects of same type, which
  enabled me to make functions shorter (they don't have to deal
  with each of them individualy).
* Move image size and config related functions to bbootimg.c - they
  should not be in the library.
* Document all library functions
* Clean-up the API

[0.1.12] Properly handle fread() failure in load_part()

[0.1.11] Add support for DTB

[0.1.10] Enable combination of -f and -c arguments

* -c has to be *after* -f

[0.1.9] Add hash of 'name' to the header's id fields

[0.1.8] bbootimg: print strerror when image load fails in -i and -j

[0.1.7] Fix libbootimg_load_config_line() for lines without whitespace

* Until now, -c "name=nothing" would result in name argument
  being set to "othing" and libbootimg wouldn't check last letter
  of argument name, means that "namz = nothing" would set name
  value.

Fix trailing NULL character in JSON output