Code Improvements, Style Guidelines, Better Documentation, Minor Bug Fixes

Code/Syle Improvements
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Removed redundant command line arguments from ```server.py```

Beginning to standardize on single-quoted strings unless necessary to use double-quoted strings (**MUCH** easier to read and understand the code).

Beginning to standardize on tab-based indenting rather than space-based indenting. Each tab is 3 spaces wide so that the tabs are not ridiculously large.

Improved configurability, made documentation more easily human-readable, minor variable name changes.

Made option to set netbootDirectory parameter in ```httpd.py``` and ```tftpd.py``` so that if they are called independently or separately the directory can be passed rather than set in the main file if desired.

**NOTE:** GitHub might show larger code blocks changed than they actually were because of the conversion from spaces to tabs but any code changes are either clearly visible or detailed in this pull request.

Better Documentation
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Updated README.md to reflect argument help changes

Minor Bug Fixes
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Fixed the same default IP bug in ```httpd.py``` from ```tftpd.py``` where ```ip=''``` and changed to ```'ip='0.0.0.0'```

Fixed minor errors and hard-coded bugs in ```dhcpd.py```