Merge branch 'master' into config

* master:
  cmd/{split,save}: support any compression level using the new -# feature.
  options.py: add support for '-#' style compression options.
  Add documentation for compression levels
  Add test case for compression level
  Add compression level options to bup save and bup split
  Make zlib compression level a parameter for Client
  Make zlib compression level a parameter of git.PackWriter
  Use is_superuser() rather than checking euid directly
  Add is_superuser() helper function
  Makefile: add a PREFIX variable for locations other than /usr.

diff --combined Makefile
index 8558c772246bb9cf463b32a5a32c03b03d2c411e,7bf50feb90046595f6768785f9de4bb465c3bf3f..e04235d5f86702511d6a677b4733badcfbf8f408
--- 1/Makefile
--- 2/Makefile
+++ b/Makefile
@@@ -16,10 -16,11 +16,11 @@@ Documentation/all: bu
  
  INSTALL=install
  PYTHON=python
- MANDIR=$(DESTDIR)/usr/share/man
- DOCDIR=$(DESTDIR)/usr/share/doc/bup
- BINDIR=$(DESTDIR)/usr/bin
- LIBDIR=$(DESTDIR)/usr/lib/bup
+ PREFIX=/usr
+ MANDIR=$(DESTDIR)$(PREFIX)/share/man
+ DOCDIR=$(DESTDIR)$(PREFIX)/share/doc/bup
+ BINDIR=$(DESTDIR)$(PREFIX)/bin
+ LIBDIR=$(DESTDIR)$(PREFIX)/lib/bup
  install: all
        $(INSTALL) -d $(MANDIR)/man1 $(DOCDIR) $(BINDIR) \
                $(LIBDIR)/bup $(LIBDIR)/cmd $(LIBDIR)/tornado \
@@@ -56,17 -57,11 +57,17 @@@
  
  %/clean:
        $(MAKE) -C $* clean
 +      
 +config/config.h: config/Makefile config/configure config/configure.inc \
 +              $(wildcard config/*.in)
 +      cd config && make config.h
  
  lib/bup/_helpers$(SOEXT): \
 +              config/config.h \
                lib/bup/bupsplit.c lib/bup/_helpers.c lib/bup/csetup.py
        @rm -f $@
 -      cd lib/bup && LDFLAGS="$(LDFLAGS)" CFLAGS="$(CFLAGS)" $(PYTHON) csetup.py build
 +      cd lib/bup && \
 +      LDFLAGS="$(LDFLAGS)" CFLAGS="$(CFLAGS)" $(PYTHON) csetup.py build
        cp lib/bup/build/*/_helpers$(SOEXT) lib/bup/
  
  .PHONY: lib/bup/_version.py