enhance optimizer: detect eq-comparison for syslog facility

... and replace it with a (much faster) prifilt() call
script optimizer: support NOT pri matches
script optimizer: optimize and/or on PRI filters
bugfix: optimizer stopped prematurely on some operations
script optimizer: severity eq/ne to prifilt()
script optimizer: severity lt/le/gt/ge to prifilt()
script optimizer: support numerical facilities in compare operations as well
script optimizer: support textual severities in compare operations as well
build: fix uuid configure check
build: drop obsolete --enable-pthreads configure switch

Building without pthreads support hasn't been support for a while.
build: link omelasticsearch against -lm

Use LT_LIB_M to find the math library which is needed for pow().
bugfix: invalid DST handling under Solaris
Merge branch 'v5-stable' into v6-stable

Conflicts:
	ChangeLog
Merge branch 'v6-stable' into v7-stable
doc: mention recent patches in ChangeLog
Merge branch 'v7-stable'
Merge branch 'master-optimize-facilitext'
minor cleanup
ommysql: addd batching/transaction support
fix some compile problems on some platforms