Replace lcov -r commands with faster way

Instead of using lcov -r (which is extremely slow), first use a python script to perform bulk cleanup of the /usr/include/* coverage. Then use lcov -a to remove the duplicate entries. This has the same effect of lcov -r but runs significantly faster

contrib/filter-lcov.py

@@ -0,0 +1,24 @@
+#!/usr/bin/env python3
+
+import argparse
+
+parser = argparse.ArgumentParser(description='Remove the coverage data from a tracefile for all files matching the pattern.')
+parser.add_argument('pattern', help='the pattern of files to remove')
+parser.add_argument('tracefile', help='the tracefile to remove the coverage data from')
+parser.add_argument('outfile', help='filename for the output to be written to')
+
+args = parser.parse_args()
+tracefile = args.tracefile
+pattern = args.pattern
+outfile = args.outfile
+
+in_remove = False
+with open(tracefile, 'r') as f:
+    with open(outfile, 'w') as wf:
+        for line in f:
+            if line.startswith("SF:") and pattern in line:
+                in_remove = True
+            if not in_remove:
+                wf.write(line)
+            if line == 'end_of_record\n':
+                in_remove = False