Option to dump log of norms of GSO vectors to file during execution

- add dumpGSO() function for writing log of GSO norms to file
- add -bkzdumpgso <filename> option
Merge pull request #3 from malb/master

Fix bug in reporting of cputime when BKZ_VERBOSE is set
Merge branch 'master' into dump-gso
Merge pull request #2 from malb/dump-gso

Option to dump log of norms of GSO vectors to file during execution
Moved reformat scripts to a tools directory
Add plot_gso_dump.py file to for plotting outputs of "-bkzdumpgso"

The script requires matplotlib to be installed.