add merge file, but has bug
Merge branch 'xie'
add the function of merging file,not add write file
split the Merge class from llvm-prof.cpp
split the Merge class from llvm-prof.cpp
split the Merge class from llvm-prof.cpp
add writer totle file
Modify the code and add the write of CommandLines
Merge pull request #1 from HaoMengHIT/master

add --merge used for merge llvmprof.out s