Merge r1597642, r1608999, r1605207, r1610366, r1610353, r1611871 from trunk:

Rename module name in doxygen + partly revert r832442 which skipped doxygen doc generation for 'mod_watchdog.h'

s/apr_pstrndup/apr_pstrmemdup/ to save a few cycles

Use ap_remove_input_filter_byhandle instead of duplicating the code.

Remove some 'register' in variable declaration.

Remove some 'register' in variable declaration.
Save a few cycles by calling 'apr_isalnum' instead of 'apr_isalpha' and 'apr_isdigit'.

Do not use deprecated define.

No change in generated code because MODULE_MAGIC_NUMBER is defined as:
   #define MODULE_MAGIC_NUMBER MODULE_MAGIC_NUMBER_MAJOR
Submitted by: jailletc36
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1622705 13f79535-47bb-0310-9956-ffa450edef68