add NestedCatalogNotFound exception
keep track of compressed file handle
Catalog knows about own content hash
extra checks in Catalog._check_validity()
Catalogs can be closed after usage (ulimit -n)
CompressedObject.get_compressed_file()
convenience function cvmfs.open_repository()
get the nested catalog count
traverse catalogs rooted anywhere
python tools can load catalog's predecessor
TEST: regression test for CVM-667
FIX: SignatureManager::LoadPublicRsaKeys() can ignore broken keys
TEST: adapt for restrictive version
SignatureManager::LoadPublicRsaKeys() fails on broken keys
FIX: SELinux context not set properly
Merge pull request #546 from reneme/fix-slc5_x64

FIX: SELinux Context not set Properly in SLC5 x64 Test Setup
add CI scripts for building with Jenkins
rename decompress_tmp_dir to tmp_dir
FIX: do catalog crunching in /var/spool
set permissions for cvmfs_cache_t