Delayed 2017 Spring clean release

• Restructured repo to make packaging more straightforward
• Updated build scripts
• Windows binaries now built on Linux using Wine
• Added installation with pip
• Fixed detection of surrogate pairs in Py3
• Fixed exception with images with Intellectual Property Box
• Improved handling of codestream comments with non-text data
• Various code clean-ups based on PEP8 and PyLint analysis
• Removed outdated build scripts (esp. Windows batch files)