Moving debian specific patches to subdirectory within patches directory.

Signed-off-by: Daniel Baumann <daniel@debian.org>

debian/patches/debian/0001-build.patch

@@ -0,0 +1,19 @@
+Author: Daniel Baumann <mail@daniel-baumann.ch>
+Description: Avoid overwriting build-environment.
+
+diff -Naurp pdlzip.orig/configure pdlzip/configure
+--- pdlzip.orig/configure
++++ pdlzip/configure
+@@ -21,9 +21,9 @@ datarootdir='$(prefix)/share'
+ infodir='$(datarootdir)/info'
+ mandir='$(datarootdir)/man'
+ CC=gcc
+-CPPFLAGS=
+-CFLAGS='-Wall -W -O2'
+-LDFLAGS=
++#CPPFLAGS=
++#CFLAGS='-Wall -W -O2'
++#LDFLAGS=
+ 
+ # checking whether we are using GNU C.
+ if /bin/sh -c "${CC} --version" > /dev/null 2>&1 ; then true