Bug 168346

When a user navigates from a "Memory Leaks" window to a malloc that is problematic then it would be nice to help a user
to see "free" corresponding to this malloc. It was obvious that this feature is lucking during the usability study. 
Technically we need to use "Find usages" engine to do this.
I can envision a few ways how to present it to a user:
1) When navigating to a 
  complex* t = malloc(sizeof(complex));
  a suggestion tip appears "Find deallocations", and if user clicks then something like find usages of free(t) is invoked.
2) A tool tip on any malloc or new always shows hyperlinked search results of frees or deletes
3) In memory leak window every line has a [+] on the left. When expended we do the find usages.