Remove extern_function

The source file was not compiled due to a preprocessor switch and the
header file was included nowhere.
Remove EnumSerialPorts()

Used nowhere, was replaced by GetSerialComPortNumber1
Remove commented out version of GetTempUnit
Remove  is_a_float_str

Not used anywhere
Remove get_unit_a_str

Not used anywhere
Remove button_load_bitmap

Not used anywhere
Remove message_box_function()

Not actually used anywhere.

One call in some code that is not compiled - I have replaced it there
with the windows API call it was wrapping.
Remove Get_SerialNumberA

Not used anywhere
Remove clear_a_char_array

Not used anywhere
Remove judgement_file_or_path_exist

Not used anywhere
remove SetPaneCommunicationPrompt

Not used anywhere.

Multiple commented out calls in MainFrm.cpp only, so I have commented
this out and moved it to that file.
Remove get_units_from_now_range

Not used anywhere
Remove delete_folder

Not used anywhere
Remove 3 unused format conversions
Remove unnecessary include of MainFrm.h

globle_function.cpp now compiles cleanly without generating any warnings
Merge remote-tracking branch 'origin/master' into DeadGlobals

Conflicts:
	T3000/MainFrm.cpp
Merge pull request #17 from JamesBremner/DeadGlobals

Remove dead free global functions