Adding back Flash/NPAPI support

[K4sum1]

I was requested to do this, however this is a big task, would add a bunch of complexity, and deviates quite a bit from the main idea of being a Windows 7 compatible browser. However if someone is willing to pr flash support back in, and maintain it, maybe only for ESR, then I would be willing to merge it.

All related commits that I can find from bugzilla: https://hg.mozilla.org/mozilla-central/rev/9036b58142b50ecf80a42c6e8968a387a84c51cd https://hg.mozilla.org/mozilla-central/rev/c0ff7dbb807e2c2e57fbcdae68b8b70942886b04 https://hg.mozilla.org/mozilla-central/rev/847bd43fd835e0ef3eb3b25aacf0d0ebf2b97b67 https://hg.mozilla.org/mozilla-central/rev/ebcfcf919663 https://hg.mozilla.org/mozilla-central/rev/1c07317c6dbf https://hg.mozilla.org/mozilla-central/rev/080aa7b074c3 https://hg.mozilla.org/mozilla-central/rev/3739f10fd744 https://hg.mozilla.org/mozilla-central/rev/8f1aa45d854b https://hg.mozilla.org/mozilla-central/rev/11170fb7e7fe https://hg.mozilla.org/mozilla-central/rev/4dba093cbb34 https://hg.mozilla.org/mozilla-central/rev/29ce5e7ceaa6 https://hg.mozilla.org/mozilla-central/rev/a5d8b38876d8 https://hg.mozilla.org/mozilla-central/rev/d789ce825491 https://hg.mozilla.org/mozilla-central/rev/32a2fdad82bb https://hg.mozilla.org/mozilla-central/rev/6e00aba7e14f https://hg.mozilla.org/mozilla-central/rev/ee8836383bf0 https://hg.mozilla.org/mozilla-central/rev/2e011ce4adbf https://hg.mozilla.org/mozilla-central/rev/4639cb0ba184 https://hg.mozilla.org/mozilla-central/rev/c76b18432fa2 https://hg.mozilla.org/mozilla-central/rev/ac573562d3df https://hg.mozilla.org/mozilla-central/rev/f2ad1724e9af https://hg.mozilla.org/mozilla-central/rev/ee8b4ffc4aca https://hg.mozilla.org/mozilla-central/rev/6999a4083233 https://hg.mozilla.org/mozilla-central/rev/a0b2f4d23544 https://hg.mozilla.org/mozilla-central/rev/2155fb99d845 https://hg.mozilla.org/mozilla-central/rev/36306d2ee01f https://hg.mozilla.org/mozilla-central/rev/654058730d71 https://hg.mozilla.org/mozilla-central/rev/196e52cf4488 https://hg.mozilla.org/mozilla-central/rev/5b8bfc8a569a https://hg.mozilla.org/mozilla-central/rev/aaf121bd46d1 https://hg.mozilla.org/mozilla-central/rev/81361995e7ed https://hg.mozilla.org/mozilla-central/rev/b9d74690e7f1 https://hg.mozilla.org/mozilla-central/rev/ebde9f72db43 https://hg.mozilla.org/mozilla-central/rev/9e6b2af2a4c9 https://hg.mozilla.org/mozilla-central/rev/46ff02acf7be https://hg.mozilla.org/mozilla-central/rev/87c164e0c093 https://hg.mozilla.org/mozilla-central/rev/bdcbb8d22b91 https://hg.mozilla.org/mozilla-central/rev/e39ed1138976 https://hg.mozilla.org/mozilla-central/rev/0c47e25d063f https://hg.mozilla.org/mozilla-central/rev/78c4b82a3015 https://hg.mozilla.org/mozilla-central/rev/8f2595f0dfda https://hg.mozilla.org/mozilla-central/rev/172084df9b2b https://hg.mozilla.org/mozilla-central/rev/72421ad7ff7b https://hg.mozilla.org/mozilla-central/rev/2c9db4cd3d89 https://hg.mozilla.org/mozilla-central/rev/d3ddd7384de2 https://hg.mozilla.org/mozilla-central/rev/af42b96cd2b8 https://hg.mozilla.org/mozilla-central/rev/4b6c96d212f4 https://hg.mozilla.org/mozilla-central/rev/6ec93ada1e62 https://hg.mozilla.org/mozilla-central/rev/bc1cc01f5898 https://hg.mozilla.org/mozilla-central/rev/a43143cd7a24 https://hg.mozilla.org/mozilla-central/rev/64e6fc7cfaeb https://hg.mozilla.org/mozilla-central/rev/3f1967bdcd23 https://hg.mozilla.org/mozilla-central/rev/5ca239d1722f https://hg.mozilla.org/mozilla-central/rev/00755ad9503e https://hg.mozilla.org/mozilla-central/rev/9a2b5d6683a0 https://hg.mozilla.org/mozilla-central/rev/99d3a8e44368 https://hg.mozilla.org/mozilla-central/rev/1ae388d5e3d3 https://hg.mozilla.org/mozilla-central/rev/4edb5320e3fe https://hg.mozilla.org/mozilla-central/rev/2ecfe9d9e074 https://hg.mozilla.org/mozilla-central/rev/1fc719dc7f9f https://hg.mozilla.org/mozilla-central/rev/281695ebfa30 https://hg.mozilla.org/mozilla-central/rev/b7c00efa0444 https://hg.mozilla.org/mozilla-central/rev/dd546e629214 https://hg.mozilla.org/mozilla-central/rev/c07b32cdfb47 https://hg.mozilla.org/mozilla-central/rev/3c894371eace

https://github.com/mozilla/gecko-dev/commit/6b176f598713c7c9005955aee39b1cb4cd7f03be

[jasonliul]

Second your motion.

[greyrat116]

NPAPI plugins in Youtube https://www.youtube.com/watch?v=b-6MczEoa6I