Fix overflow in adb_client

Credit: Joshua Drake
Bug: 12060953

(cherry picked from commit e89e09dd2b9b42184973e3ade291186a2737bced)

Change-Id: I8a9b2592a5e4f7527c607abfe4ea6df6eb550aa8
Add a restorecon_recursive built-in command to init.

Functionally equivalent to the restorecon -R toolbox command.
A use case is given by:
I48eaa2b9901ac8c978192c14493ba1058a089423

Also, fix error handling and documentation for restorecon command.

Change-Id: Ia7fbcc82645baf52c6bff0490d3492f458881cbb
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Merge remote-tracking branch 'CyanogenMod/cm-11.0' into cm-11.0