Improve global and code structure using modules.

Comment and reorganize globals.py
Tests consistently use globals module for OPTions.
Add characterizer as module support.
Modify unit tests to reload new characterizer for ngspice/hspice.
Enable relative and absolute config file arguments so you can run
openram from anywhere on any config file.

compiler/characterizer/charutils.py

@@ -1,8 +1,6 @@
-import globals
 import re
 import debug
-
-OPTS = globals.get_opts()
+from globals import OPTS
 
         
 def relative_compare(value1,value2,error_tolerance=0.001):