Fix building on 4.4

Change-Id: I85030de3dea5f2d1a187cf2ced9517b3c820266a
fstrim: sync with busybox master (now an official applet)

fstrim: Needs to fire at the mp, not bd

It's a filesystem thing from this perspective.

fstrim: Indicate failure on error

Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

Change-Id: Icffb851cbe1895523e67e5ff18c67f9109a46a28
fstrim: use new-style config/kbuild/applet snippets; trim help text

function                                             old     new   delta
packed_usage                                       29546   29520     -26

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

Change-Id: I758c91f2054d1f2876fc1446f8f0afd8bffd2611
android: add a script to regenerate prebuilt config

since x86 CROSS_COMPILER removal, it can be hard to do that properly

Change-Id: I6011e3b4dac5b5e670385df4812baf32f2e5ebc5
update config, change version suffix

Change-Id: I3455772c65bbd2e1102ec1f2d9c55f4d91b702d8
build: ignore selibs pkgconfig on android builds

This cause errors and is not required

Change-Id: If6cc6fb1595e83fac452d8a28cb4b8d250dff06d
Apply post-1.21.0 patches, bump version to 1.21.1

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

Conflicts:
	Makefile