Merge pull request #303 from fancycode/githook_non_checkout

Only install git hook if cloned from git.

autogen.sh

@@ -1,10 +1,12 @@
 #!/bin/sh
 
+if [ -d ".git/hooks" ]; then
     # the pre-commit hook performs various formatting checks
     if test ! \( -x .git/hooks/pre-commit -a -L .git/hooks/pre-commit \); then \
         rm -f .git/hooks/pre-commit; \
         ln -s ../../src/hooks/pre-commit.hook .git/hooks/pre-commit; \
     fi
+fi
 
 if [ -x "`which autoreconf 2>/dev/null`" ] ; then
    exec autoreconf -ivf