build: Allow building with OpenJDK

My local builds with OpenJDK have been successful - no
reason to disallow it, let's go free...

Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>
definitions.mk: Don't fail if xmllint isn't installed

This is a workaround for xmllint currently not being installed on the
build slaves. It should be reverted when this is fixed, as it eliminates
a check for sane code.

Change-Id: I46eeadebd931ee1b6812a9eb933ee4b56ebd16a7
Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>

Conflicts:
	core/definitions.mk
build: Make sure boot.img depends on the kernel having been built

Change-Id: Ia439ed4079ef912c42aa15cac995741fd6071f1e
Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>
envsetup: add quotes around PROMPT_COMMAND

Better compatibility for zsh.

Change-Id: Ie010c30580e67e3b5357e3cc869114a525762677
Create armv6-vfp.mk
Create armv6j.mk