[WIP] Initial ConPTY support

[ForNeVeR]

TODO:

• [x] use this suggestion from Microsoft when starting a process

  (this is supposed to fix tests and run when ConPTY is used from a process with already redirected stdout)

• [x] prepare and pass the command line in ConPtyProcess constructor (https://github.com/JetBrains/pty4j/pull/108/files#diff-82050063be2c03f2db8111ba3e3cc87b433a334bfaf17817ae0d38088a4709a9R40)
• [ ] call ConPtyPrcess::destroy at the right moment of time (after the process termination it seems?)
• [x] check the code in ConPtyProcess::dispose (ConPTY documentation suggests to drain the pipes before destroying the pseudoConsole)
• [x] support input and output streams (as of now, they are ignored)

[segrey]

Thanks!