1. Introduce new applet: imgtool for better separation from the main program
2. Actually mount the image and check statvfs for free space in the image
This shall eliminate any possible module installation failure from image resizing issues.
Some functions, like `patch_init_rc()`, treat buffers read into memory
as a string instead of a byte buffer. Since the buffers weren't
NULL-terminated, this resulted in out-of-bounds reads and caused crashes
in certain conditions.
THis commit updates fd_full_read() to always NULL-terminate the buffers
so that they can be treated as strings when working with text files.
Signed-off-by: Andrew Gunnerson <andrewgunnerson@gmail.com>
