mkbootimg: support longer kernel command lines

We can't simply increase the value of BOOT_ARGS_SIZE since that
would break past binary compatibility; the offset of 'id' would
change. This can cause serious problems with incremental OTA updates.

Instead, define a supplemental field which stores command line
information beyond the first 512 bytes. A value of 1024 was chosen
to keep the total size of struct boot_img_hdr under the smallest
page size of 2048 bytes.

Even if the extra_cmdline field is used, the original cmdline
field is still always NULL-terminated to avoid issues with older
bootloaders that haven't been updated.

init kernel command line parser was limited to 1024 bytes, increase
to the new maximum.

Change-Id: I887e6f1db351a5b71a61e3a03363cf8856123d74
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Handle policy reloads within ueventd rather than restarting it.

Restarting ueventd upon policy reloads has reportedly created
stability problems for some users and could cause events to be lost.
Stop restarting ueventd and instead handle policy reloads within ueventd.

Also stops restarting installd upon policy reloads.

Change-Id: Ic7f310d69a7c420e48fbc974000cf4a5b9ab4a3b
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>

Conflicts:

	rootdir/init.rc