Serialize initialize and terminate functions

- Add wp_tegen.w
  - Include wp_tegen_initialize to initialize all submodules in the
    correct order
  - Include wp_tegen_terminate to terminate all submodules in the
    reverse order of their initialization
- Change pattern to access wp_get_txn_head() to static locals with NULL
  check
- Change documentation for many wp_memory sections
- Add total to wp_memory diagnostic struct wp_memory_diagnostics
- Rename some sections in wp_memory.w for consistency
- Update wp_memory_tests to account for struct wp_memory_diagnostics
  total
- Update wp_test.w initialize and terminate functions with correction
  for wp_test_atexit and relocation of wp_test_initialized flag for
  consistency with other initialize functions
- Add check to wp_test_execute_tests for wp_test_initialized. This is a
  pattern we'll need to follow from now on. I'll adjust the code in
  other modules at a later time
- Change wording of wp_test.w initialize and terminate section to
  account for the new wp_tegen.w module
- Change Makefile.am to include wp_tegen.w
- Add objdump output to new ./asm folder
- Move *.s to new ./asm folder