Logging: summarise repeated applications of rules

Summarise repeated applications of rules by displaying the rule once
with the number (n) of applications appended c.f. repeating the rule n
times. Enhances log readability and reduces any need to manually clear
for performance reasons.
Merge branch 'master' of https://github.com/increpare/PuzzleScript into dev
Merge pull request #103 from mechturk/dev

Logging: summarise repeated applications of rules