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

srcpkgs/kernel-libc-headers/patches/fix_scsi_varlen_cdb_hdr.diff

@@ -0,0 +1,19 @@
+Replace u8 with __u8 to make this not fail in dependent packages.
+
+--- include/scsi/scsi.h.orig	2009-10-04 19:19:45.667037936 +0200
++++ include/scsi/scsi.h	2009-10-04 19:20:01.397017561 +0200
+@@ -142,10 +142,10 @@ struct scsi_cmnd;
+ 
+ /* defined in T10 SCSI Primary Commands-2 (SPC2) */
+ struct scsi_varlen_cdb_hdr {
+-	u8 opcode;        /* opcode always == VARIABLE_LENGTH_CMD */
+-	u8 control;
+-	u8 misc[5];
+-	u8 additional_cdb_length;         /* total cdb length - 8 */
++	__u8 opcode;        /* opcode always == VARIABLE_LENGTH_CMD */
++	__u8 control;
++	__u8 misc[5];
++	__u8 additional_cdb_length;         /* total cdb length - 8 */
+ 	__be16 service_action;
+ 	/* service specific data follows */
+ };