ycmd watchog timer now wiser about machine sleep

We now make sure we don't terminate ycmd if we skipped a watchdog wakeup
time. If we skipped a check, that means the machine probably went to sleep and
the client might still actually be up. In such cases, we give it one more wait
interval to contact us before we die.
Remove clang_includes folder
Merge pull request #903 from Valloric/watchdog-fix

ycmd watchog timer now wiser about machine sleep
Don't pass extra include path to libclang
CSharp GoTo was off by one column and line
Merge pull request #917 from mispencer/CsGotoOffOneLineColumn

CSharp GoTo is off by one column and line
Detach from controlling terminal to avoid receiving SIGINT.
Add libclang builtin headers for LLVM release 3.3 and 3.4

Copied from the ./lib/clang/3.X/include directories of the prebuilt binary releases at llvm.org, specifically
http://llvm.org/releases/3.3/clang+llvm-3.3-amd64-Ubuntu-12.04.2.tar.gz and http://llvm.org/releases/3.4/clang+llvm-3.4-x86_64-linux-gnu-ubuntu-13.10.tar.xz.

These headers don't appear to be arch dependent, so we should be good.
Add builtin includes for AppleClang 5.1

Copied from Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib
Use OnWindows from utils instead of ad-hoc platform check.
Merge pull request #918 from m4burns/master

Detach from controlling terminal to avoid receiving SIGINT.
Merge pull request #910 from nickhutchinson/fix-libclang-includes

Fix libclang's #include search path
More strongly condemn use of system libclang
Revert "Add builtin includes for AppleClang 5.1"

This reverts commit c62bb98f4f4ca52fcb765bb81b526ceb433ae157.
Revert "Add libclang builtin headers for LLVM release 3.3 and 3.4"

This reverts commit 2f84503a99bc1be474719d42ffdc42e5d0de215b.
Revert "Don't pass extra include path to libclang"

This reverts commit 7bdff8941c1bcb8df3badbef403927211cb3391a.
Revert "Remove clang_includes folder"

This reverts commit cca4785fb69740f36b6d07280d2fb4d6dc039e62.
GoTo commands now work with C-family macros

Fixes #758
Prevent setsid() failure from taking down ycmd
Only adjust updatetime if above 2000.

Goal is to lower it so don't raise it if already low.

Closes #834