fix utf8 NBSP in header comments
irecovery: fix /execute command and add error checking when reading files
libirecovery: Return "invalid input" instead of unknown error in irecv_getenv()
irecovery: Show mode on /ideviceinfo command and add mode_to_str() helper
irecovery: Fix formatting style for shell usage and improve usage summary text
irecovery: Rename /exploit into more accurate /limera1in command