CPM File Uploader in Python - with directory upload feature

[mchobby]

Created a Python version of btc utility. Tested on Linux.

Here the features:

• same basic features as c version PLUS
• can create output file (ASCII encoding) with HEX content
• can send HEX content over serial connection (with 1ms pause between characters)
• can send HEX to stdout (terminal) when no output and no device are selected
• can force CR or LF to CRLF (for text file)
• can read/write file in/to subdirectory or absolute path. Only the filename is kept for CP/M name.
• can send several files at once by using a wildcard in filename (see help or examples in readme file).