Debian packaging fixes suitable for 0MQ git

Removed README.source, TODO.source since these are irrelevant to a generic
git package.
Fixed spelling in debian/copyright.
Removed RFC check in debian/rules, again irrelevant to a generic git package.

debian/README.source

-The source of this package is managed by using a hgpkg managed
-mercurial repository at https://fortytwo.ch/hg/pkg-zeromq.  (hgpkg is
-currently included in the debian/ directoriy here and not separately packaged,
-since it's not widely used yet.)
-
-Typically, you'd start by:
-
- $ wget TODO get upstream tarball
- $ hg clone https://fortytwo.ch/hg/pkg-zeromq zeromq
- $ debian/hgpkg build
-
-Description: the repository contains an "upstream" and a "default" branch;
-"upstream" is directly imported from upstream's svn, and the default branch
-contains the directory as it is to be packed by dpkg-source.
-
-So far, the upstream source is unpatched.
-
-Upstream is at:
-    http://www.zeromq.org/
-
-Import a new upstream version:
-
- $ debian/hgpkg import <path/to/tar>
-     (<path/to/tar> is the upstream tarball to be imported; the upstream
-      version is extracted from the tarball filename.  The import will switch to
-      the upstream branch, import, and switch back, and leave the uncommitted
-      merge on the default branch.)
-   -> now examine the merge, correct packaging issues, edit debian/changelog if
-      necessary.
- $ hg ci -m "new package version"
- $ debian/hgpkg build
-   -> if the package is good:
- $ debian/hgpkg markdeb
-
-(arguably a mercurial bug: you'll get a merge conflict in .hgtags during
-upstream import which you'll have to correct manually.)
-

debian/TODO.source

-* use external openpgm instead of included one
-  -> openpgm doesn't include obvious build instruction and I don't really know
-     scons or cmake.  Postponed for now.
-* use external XmlParser instead of included one
-  -> Not sure, only makes sense if it is used somewhere else.

debian/copyright

@@ -35,7 +35,7 @@ License:
 On Debian systems, the complete text of the GNU Lesser General
 Public License can be found in `/usr/share/common-licenses/LGPL'.
 
-iMatrix also offers commercial licenses for 0MQ.
+iMatix also offers commercial licenses for 0MQ.
 
 
 Licensing information for the included OpenPGM library

debian/rules

@@ -20,12 +20,6 @@ configure: configure-stamp
 configure-stamp:
 	dh_testdir
 
-	# hack: check that we're building from dsfg-free orig tarball
-	if tar tzf foreign/openpgm/libpgm-*.tar.gz | grep -q rfc3208.txt;then \
-	    echo "Remove RFC documents from orig tar."; \
-	    exit 1; \
-	fi
-
 	./configure $(CROSS) \
 	    --prefix=/usr \
 	    $(pgm_opt) \