Following up on r36334,r36336, resolve the delay caused by re-initializing COM, by initializing COM only when it is really needed and just one time.
Following up on r36334,r36336, resolve the delay caused by re-initializing
COM, by initializing COM only when it is really needed and just one time.

This removes the COM initialization for all trivial character sets like
the default charset, the current character set, UTF-8 and numeric charsets.

* subversion/libsvn_subr/win32_xlate.c
  (includes): Include private/svn_atomic.h
  (com_initialized): New static variable to keep com initialization state.
  (initialize_com): New function.
  (get_page_id_from_name): Initialize COM if a named charset name must be
    converted.
  (svn_subr__win32_xlate_open): Stop initializing and uninitializing COM
    on every call.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@876411 13f79535-47bb-0310-9956-ffa450edef68

wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion