Don't copy all git history

[helpau]

Cloning time: before-266 seconds, after-58 seconds, folder size: before-984 MB, after-619 MB

[ckrause]

The git history is needed to collect the latest added program IDs:

loda-cpp/src/seq/seq_program.cpp

Line 76 in 930e6c2

UIDSet SequenceProgram::collectLatestProgramIds(size_t max_commits,

The miner uses this information to prefer mutating recently added programs. This accelerates the mining process.

[helpau]

The git history is needed to collect the latest added program IDs:

loda-cpp/src/seq/seq_program.cpp

Line 76 in 930e6c2

UIDSet SequenceProgram::collectLatestProgramIds(size_t max_commits,

The miner uses this information to prefer mutating recently added programs. This accelerates the mining process.

Fixed. What do you think about current version of PR?

[ckrause]

Please don't include stats.hop in git.cpp. Replace the "fast" parameter by an int parameter for the number of commits. The default should be -1 which means full clone. Check where the clone function is called and explicitly set the parameter to the new constant.