Check if -XL or -PP should be specified

[tobya]

now that XL and PP files can be converted it is easy to load a xls file an doutput a csv and wonder why you get errors because you ahve forgotten -XL so -WD is used.

• Output help string to specify that WORD or EXCEL converter is being used
• Check if filetype is a normal XL or WD file type and break unless something specified.

[tobya]

Related to #92

[tobya]

Very simple change to error output , specify that word is being used. This indecated that thats where the issue may lie