use separate pool for history generation of renamed files
fixes #751
use separate tunable for thread pool size for handling renamed files
Merge pull request #752 from vladak/thread_pools

Thread pools
Seach the vb directory for a list of visual basic reserved words.
Without this, the VB analyser will fail at runtime because the file
is missing
Merge pull request #753 from bbaetz/pom-include-vb

Search the vb directory for a list of visual basic reserved words.