CMSSW_7_6_7

Changes since CMSSW_7_6_6_patch1:

CMSSW_7_6_6_patch1...CMSSW_7_6_7

• #23895 from @hvanhaev: backport of CASTOR rechitcorrector and noise simulation fixes reconstruction simulation

• #17435 from @alja: 76X Fireworks: Update URL with samples for US users visualization

CMSDIST Changes between Tags REL/CMSSW_7_6_6_patch1/slc6_amd64_gcc493 and REL/CMSSW_7_6_7/slc6_amd64_gcc493:

cms-sw/cmsdist@REL/CMSSW_7_6_6_patch1/slc6_amd64_gcc493...REL/CMSSW_7_6_7/slc6_amd64_gcc493

• cms-sw/cmsdist#2823 from @cms-sw: disable python for xroot
• cms-sw/cmsdist#2734 from @cms-sw: Update xrootd to version 4.5.0
• cms-sw/cmsdist#2726 from @cms-sw: update frontier client to 2.8.20
• cms-sw/cmsdist#2570 from @iahmad-khan: updates xrootd to 4.4.1