Increase the maximum report size to 256KB.

The original cap was sized according to standard usage patterns,
however, given an unusually large number of binary images it was
possible to hit the 64KB limit, causing the report to be truncated
prior to writing all binary images.

This actually occured with a specific managed runtime platform that
loads an extremely large number of (~500) extensions as dynamic images,
along with linking to the majority of system frameworks on Mac OS X.
The result was a total number of 788 loaded images, and a report size
of 97KB.

Issue: PLCR-529
Merge branch 'release/plcrashreporter-1.2'

Merging the fix for PLCR-529 to master.