This will be used by the bots to get adb and the NDK.

BUG=26

Change-Id: Iae07a380c49b4990f0aa7d73c4f0b399924b9784
Reviewed-on: https://boringssl-review.googlesource.com/7986
Reviewed-by: Adam Langley <agl@google.com>

Sync a few changes with the upstream one, notably get_toolchain_if_necessary.py
needs GYP_MSVS_VERSION set. Also pull the variables that change up to the top.
This diverges a bit more from the upstream one, but we're already heavily
diverged. If we ever need to support two concurrent toolchains, I'll bring us
closer to parity.

Change-Id: I6db7fbaccd5dddd92ad2deee15bd6dd3e28841f7
Reviewed-on: https://boringssl-review.googlesource.com/7830
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>

Built from:
92c83ad8a4fd6224cf6319a60b399854f55b38ebe9d297c942408b792b1a9efa  cmake-3.5.0.tar.gz

Update instructions in the UPDATING file.

Change-Id: I49d3f5ef353347c446a04797719227e9793e3e0d
Reviewed-on: https://boringssl-review.googlesource.com/7414
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>

See 0d5e080ab9 for the previous version. Include
instructions on where to get the tools used.

807f96230c889b10f2957a47585426af4cdb116a8a77f1caecca83b7d7ab862b  cmake-3.5.0-win32-x86.zip
e6bb5c3e4d936bb1067560a58a21260693a0fbe34e55afb0111fe14f7eebc92c  strawberry-perl-5.22.1.2-32bit-portable.zip

Change-Id: I504cf779abce26087d09c0c974fb481886c9c459
Reviewed-on: https://boringssl-review.googlesource.com/7413
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>

Update the easy ones here. Also include instructions on how to do this. The
.sha1 files will be updated separately with instructions.

Change-Id: I2a3aba43b8ffbdf930b8a2602dc1460077f6d0e7
Reviewed-on: https://boringssl-review.googlesource.com/7412
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>