LiteX rebased onto Migen, improving documentation, plus Google Summer of Code!

[Tim 'mithro' Ansell]

Hello!

This is just a FYI that as of commit cacbf40 - Merge pull request #415 from mithro/new-litex we have a substantial step towards "unforking" LiteX and Migen+MiSoC

This change makes it so that LiteX now uses upstream Migen rather than containing it's own fork of the Migen code. This means you should be able to refer directly to the Migen manual (at https://m-labs.hk/migen/manual/) without needing to do any translation in your head.

For the moment, LiteX still contains a large amount of forked MiSoC code but we are hoping to reduce that duplication in the future. Using upstream Migen will make it substantially easier for this to happen and for LiteX and MiSoC to be each other too.

The downside is that this merge may have introduced regressions on things that previously worked. Please do report bugs if you find them!

A big thank you to Florent who did the majority of the upstream work and to William 'cr1901_modern' Jones who did the work to update the LiteX-BuildEnv and HDMI2USB-litex-firmware repos.

On another positive note, we are working to both improve the LiteX and related echo system documentation plus make it easier to find the documentation when needed. 

For this reason we have been moving a lot of the scattered documentation into the LiteX-BuildEnv Wiki here -> https://github.com/timvideos/litex-buildenv/wiki 

Auto-generated API documentation will hopefully be published on ReadTheDocs in the next coming weeks too -> http://litex-buildenv.readthedocs.io

Lastly, the TimVideos organisation is participating in Google Summer of Code (GSoC) again this year. GSoC is a program were Google gives stipends to University students for contributing to open source projects. This means that if you are a University student or know a University student, you could get money to help make LiteX, LiteX-BuildEnv and HDMI2USB better!

You can find a precrafted set of ideas here -> https://github.com/timvideos/getting-started/issues and i.mproving things like the Linux or QEMU LiteX would certainly be eligible. However, we haven't had many students apply to work on projects like these, so it would be extremely helpful if everyone could help by reaching out to potential candidates students they know.

You can find more information about GSoC on our blog post for this year - https://hdmi2usb.tv/2018/02/26/gsoc-announcement/

There is also a lot of information on our GSoC announcement for last year too - https://hdmi2usb.tv/gsoc/fpga/hardware/python/linux/2017/03/15/gsoc-announcement/

Applications to be part of GSoC are currently open and students have until March 27, 16:00 UTC to apply!

Looking forward to an exciting northern hemisphere summer!

Tim 'mithro' Ansell