pestr: Improve performance by pre-compiling hostname patterns.
pestr: Move most of PCRE specific code to regex.h.
pestr: Store all hostname patterns in a single-linked list.
Be more verbose about pcre errors.
Merge pull request #67 from merces/v0.70-fixes

v0.70 fixes - Abstract PCRE specifics and attempt to make pestr faster by pre-compiling hostname patterns.