Updates after using cl-pcp in HPC

[JensNevens]

I was running into issues where the server process was probing the existence of a lock file, while the client process was removing this exact lock file. To counteract this issue, I have made the following changes:

• the client processes get a unique lock file for every line they process, instead of reusing the same file each time.
• the server process polls the client processes less frequent (every 0.1 second instead of every 0.01 second)

Other changes are:

• the server process cycles through the client processes such that work is more evenly distributed
• more information gets printed at the start of corpus processing
• I have updated the .asd and package.lisp files such that cl-pcp may be distributed via quicklisp