adb: Add "wait-for-sideload" command

 * Waits for connected device to enter sideload mode

Change-Id: I65b4ad86456c13a3bbc48880e12ab7a034707b88
adb: Add a few more wait-for commands

 * wait-for-recovery is obvious.
 * wait-for-online will wait for recovery || device

Change-Id: I70f747bcd201a4157b988d7ed49bcc8e5ff4c85f
ADB Logcat colored output.

This patch adds a new '-C' option to logcat so that the output is
colored with colors similar to the ones in DDMS.
Simply type "adb logcat -C" to use it.
Works well with bash in gnome-terminal.

Change-Id: Ie72199ecca0e04f2082c993f5763646bb09da61ea