Add rrdcached client support to windows + misc compatibility fixes

== Makefile / config fixes ==
* Fixed invalid AC_LANG_PROGRAM usage.
* Fixed AUTOMAKE_OPTIONS not defining subdir-objects which caused warnings
* Switched from legacy INCLUDES to AM_CPPFLAGS
* Added Makefile clean targets to ensure all autogenerated targets are removed
* Updated Makefile.PL to be more portable and less hardcoded for Win32
* Switched bash scripts to use #!/usr/bin/env bash for compatibility with none Linux OS's
* Cleaned up win32/Makefile.msc variable defines for easy updating
* Updated defines of SIZEOF_TIME_T to take into account the variances in Windows.

== Code Enhancements / fixes ==
* Added support for rrdcached client methods to windows builds
* Fixed invalid type warning for atoi assignment to a enum
* Fixed malloc cast warnings
* Fixed illegal use of this for variable
* Fixed getsockname cast warning
* Removed HAVE_CONFIG_H checks as all platforms now have it
* Removed unused skip variable from rrd_graph data_fetch
* Fixed unused var warnings for newGraphDescription params
* Fixed unused var st warning in HandleInputLine
* Fixed all includes for <stdint.h> to check HAVE_STDINT_H
* Fixed use of uninitialsed base_dir in rrd_mkdir_p on Win32
* Updated win32/README with details of obtaining stdint.h as well as locations
  for dependencies