H stage hooks are not executed in alphanumeric sorted order

[Francis Ginther]

'H' hook scripts are executed in an undefined order. os.listdir() does not return a sorted list.

Example:
DEBUG:pbuilderjenkins:Temporary hooks directory: /tmp/tmp6MNXmI
INFO:pbuilderjenkins:Running hooks
DEBUG:pbuilderjenkins:Running hook H05unity_hacks
+ '[' -f autogen.sh ']'
+ sed -i 's,^\(#\!.*\),\1\nexport DPKG_GENSYMBOLS_CHECK_LEVEL=0,' debian/rules
DEBUG:pbuilderjenkins:Running hook H40native_hack.py
DEBUG:H40native_hack:Current directory/home/ubuntu/jenkins/workspace/compiz-quantal-build-mbs-pt/build/pbuilder/distribution/quantal/flavor/amd64/work
INFO:H40native_hack:Fixing version in changelog
DEBUG:pbuilderjenkins:Running hook H04version_bump
++ awk '/^revno/ {print $2}'
++ bzr log -c -1
+ trunk_rev=3375
++ awk '/^revno/ {print $2}'
++ bzr log -c -1 lp:ubuntu/compiz
Most recent Ubuntu version: 1:0.9.8.0-0ubuntu1
Packaging branch status: CURRENT
+ packaging_rev=3297
++ sed -e 's/\(.*\)-[0-9]ubuntu.*/\1/'
++ awk '/^Version/ {print $2}'
++ dpkg-parsechangelog
+ version=1:0.9.8.2+bzr3376
+ version=1:0.9.8.2+bzr3376ubuntu0+3297
++ awk '/^Source/ {print $2}'
++ dpkg-parsechangelog
+ sourcename=compiz
+ dch -v 1:0.9.8.2+bzr3376ubuntu0+3297 'Automatic build' -D quantal
INFO:pbuilderjenkins:Chroot build starting...