unpackbootimg: leave note on extra newlines for *-header_version (osm…

…0sis#15)

mkbootimg+unpackbootimg: clean up formatting/consistency/organization

unpackbootimg: fix compile on NDK + Linux

unpackbootimg.c: In function 'detect_hash_type':
unpackbootimg.c:51:5: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
     for (int i = SHA_DIGEST_SIZE + 4; i < SHA256_DIGEST_SIZE; ++i) {
     ^
unpackbootimg.c:51:5: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code

mkbootimg: check dtb image size

- per aosp-mirror/platform_system_core@96fd887
- check all dt* image sizes
- clean up dt* error messages

unpackbootimg: fix unpacking Huawei "Cairo" signing

- Huawei boot.img has header_version=0 but "Cairo SIGN" at offset 1632 would confuse header.dtb_size so protect against this
- add similar protection for header.recovery_dtbo_size

mkbootimg: update for boot_img_hdr_v2

- switch to v2 and support new --dtb and --dtb_offset when --header_version 2 (or greater)
- pre-version switch --dt for old dt_size dt section remains for when --header_version 0 (default)
- add --recovery_acpio which is really just --recovery_dtbo in everything but the switch name

mkbootimg: update for boot_img_hdr_v1

- switch to v1 and write fields based on logic to still support v0 and pre-version images
- support --dt only when --header_version 0 (default), support --recovery_dtbo when --header_version 1 (or greater)
- elide some redundant code
- fix up some inconsistent bracing and spacing from previous PRs

unpackbootimg: work around new bootimg.h header_version conflict with…

… old dtbsize

stop-gap measure until boot_img_hdr_v1 can be properly integrated
Ref: https://github.com/aosp-mirror/platform_system_core/blob/master/mkbootimg/include/bootimg/bootimg.h

unpackbootimg: fix SIGSEGV in case of input / output file not available

Do not hardcode make for compatibility with *BSD.