As part of issue #1, we should build all libraries and programs that we
deploy into the Heads initrd. This modifies the module configurations
for all of them to install into heads/install so that we can build
against them.
Add dmsetup, cryptsetup and veritysetup (issue #46).
Build gpgv 1.4 as a standalone tool (issue #23).
Modify populate-lib to use the install directory by setting
LD_LIBRARY_PATH (issue #35).
