Add a changelog generator helper script

ps2: switch a remnant of my personal script setup to be android_build_top-relative
ps3: remove humorous digs at the author of the commit I just 'opened up a can on'
ps4: accumulate date-stamped changelogs in a directory in repo root
ps5: cleanup whitespace
ps6: aaand done

Change-Id: Ieffabf5a8dd58d8c803b20c1cda0cbe79fb33ef4
Signed-off-by: nuclearmistake <nuclearmistake@gmail.com>
add changelogger from vanir (nuclearmistake rules!)

Change-Id: I4d7984ad265a705f1d3a71a59e5f051a77fb4812
Make changelogger use FORCE_BUILD_DATE for both the differential git tags (YMD for numerical == chronological ordering), and MDY for log naming (matches nightly zip names)

Change-Id: Icb6ca4ef25ab65ccae95566f109b7347941ce846
	changelogger: Get rid of unnecessary pushd

Change-Id: Ie042e36484cf71f454c195c1f2a72a6538b889b5