sqlite3: add new searches to search.py

+  -I <I>    Get the includers of <I>
+  -i <I>    Get the includees of <I>
+  -M <C>    Get all members of class <C>
+  -B <C>    Get the base classes of class <C>
+  -S <C>    Get the sub classes of class <C>
Signed-off-by: Adrian Negreanu <adrian.m.negreanu@intel.com>