mk: Remove leading './' from manifest entries
Revert "Revert "mk: Run 'make install' through install.sh""

This reverts commit d62163188a21e5afc3d0f476eaf7856d91f715b2.

Conflicts:
	mk/install.mk
configure: Make rustlibdir non-configurable

Trying to reduce the complexity of installation
rustc: Stop relying on CFG_LIBDIR_RELATIVE

This is not sufficient for finding the library directory for binary
installs, but it does make the build more complex by requiring
env vars be set to build rustc.
mk: Rename CFG_COMPILER to CFG_COMPILER_HOST_TRIPLE

Much clearer
mk: Make nightlyism a configure option
mk: Fix deps for prepare host tools
install: Support --libdir and --mandir correctly

This adds a hack to rustc to make it find the library directory
regardless of whether it is named lib/lib64/lib32.
install: name the bundled manifest 'manifest.in'. Cleanup

The installed manifest is a different file, so they should have
different names. This should prevent various wierd conflicts in the future.
install: Don't allow installation over the install files
rustc: Fix detection of lib64 directory

Instead of just looking for its presence we need to see if it actually
contains rust stuffs.
rustc: Fix tests for sysroot changes
mk: Use 'find' invocation that works on mac
auto merge of #13151 : brson/rust/dist, r=alexcrichton,brson

A variety of stuff here, mostly aimed at making `make install` work correctly with `--libdir` and `--mandir`. `make install` again goes through `install.sh`.