xmake v2.1.1 released, support golang, dlang and rust languages

New features

• Add --links, --linkdirs and --includedirs configure arguments
• Add app2ipa plugin
• Add dictionary syntax style for xmake.lua
• Provide smart scanning and building mode without xmake.lua
• Add set_xmakever api for xmake.lua
• Add add_frameworks api for objc and swift
• Support multi-languages extension and add golang, dlang and rust language
• Add optional target_end, option_end, task_end apis for scope
• Add golang, dlang and rust project templates

Changes

• Support vs2017 for the project plugin
• Improve gcc error and warning tips
• Improve lanuage module
• Improve print interface, support lua print and format output
• Automatically scan project files and generate it for building if xmake.lua not exists
• Modify license to Apache License 2.0
• Remove some binary tools
• Remove install.bat script and provide nsis install package
• Rewrite documents using docute
• Improve os.run, os.exec, os.cp, os.mv and os.rm interfaces and support wildcard pattern
• Optimize the output info and add -q|--quiet option
• Improve makefile generator, uses $(XX) variables for tools and flags

Bugs fixed

• #41: Fix checker bug for windows
• #43: Avoid to generate unnecessary .xmake directory
• Add c++ stl search directories for android
• Fix compile error for rhel 5.10
• Fix os.iorun bug