[developers] CL-PPCRE 1.2.18

[Ben Waldron]

Ben Waldron wrote:
> We are currently using version 1.2.3 of CL-PPCRE. The most recent 
> version is 1.2.18. This incorporates a number of bug fixes (none of 
> which appear to directly affect our code). I would like to upgrade the 
> LKB to the latest version. Does anyone have any reason to want to keep 
> the current version? (tsdb tells me it is safe to upgrade.)
I've heard no objections, so I plan to go ahead and upgrade to CL-PPCRE 
1.2.18 later this week.