Major changes to not depend on cksum and db from NetBSD.

Two new utilities in C have been created:
	- xbps-digest: shows the SHA256 hash for a file.
	- xbps-pkgdb: handles dependency stuff via proplib.

Templates should use now $build_depends and change $checksum to be
a SHA256 hash. That means that I'm currently using xbps on Linux and
I lost interest on NetBSD, perhaps I'll add support for it in the
future.

Only git and its dependencies have been converted, as well as vim.

--HG--
extra : convert_revision : 53a7e030ca6b6d02bb6cd3e51d42b7d5702c1b57

templates/libtool.tmpl

@@ -7,7 +7,7 @@ distfiles="http://ftp.gnu.org/pub/gnu/libtool/$pkgname-$version@.tar.gz"
 build_style=gnu_configure
 short_desc="Generic library support"
 maintainer="Juan RP <xtraeme@gmail.com>"
-checksum=f8862338e2c6ea04332fd5aad4aad5bc35d0e152
+checksum=eb6b8f8272c5a5cad0c7c6b949aa75632f45c295f09b2e1e90b6bce15b32b796
 long_desc="
  This is GNU libtool, a generic library support script. Libtool hides
  the complexity of generating special library types (such as shared