Major infrastructure changes, part 2.

* Moved helpers, common and triggers dirs into xbps-src, where
  they belong.
* Renamed the templates dir to srcpkgs, it was so redundant before.
* Make it possible to add subpkgs with no restriction in names, for
  example udev now has a subpkgs called "libgudev". Previously
  subpkgs were named "${sourcepkg}-${pkgname}".
* xbps-src: changed to look for template files in current directory.
  That means that most arguments from the targets have been removed.
* xbps-src: added a reinstall target, to remove + install.
* xbps-src: do not overwrite binpkgs by default, skip them.

And more that I forgot because it's a mega-commit that I've been
working for some days already...

--HG--
extra : convert_revision : 0f466878584d1e6895d2a234f07ea1b2d1e61b3e

xbps-src/shutils/configure_funcs.sh

@@ -29,11 +29,9 @@
 #
 configure_src_phase()
 {
-	local f lver pkg="$1"
+	local f lver
 
-	[ -z $pkg ] && [ -z $pkgname ] && return 1
-
-	[ ! -d $wrksrc ] && msg_error "unexistent build directory [$wrksrc]."
+	[ -z $pkgname ] && return 1
 
 	# Apply patches if requested by template file
 	if [ ! -f $XBPS_APPLYPATCHES_DONE ]; then
@@ -57,6 +55,8 @@ configure_src_phase()
 		lver="${version}"
 	fi
 
+	cd $wrksrc || msg_error "unexistent build directory [$wrksrc]."
+
 	# cross compilation vars.
 	if [ -n "$cross_compiler" ]; then
 		. $XBPS_SHUTILSDIR/cross-compilation.sh