Fix building on Solaris.

"SunOS" and "Solaris" are the same thing these days, so make them go
down the same code paths. In particular, the browse feature was omitted
on solaris but not sunos5, causing trouble for some folks (see #838).
set *err when too many components in CanonicalizePath
whitespace/comment/wrap fixes, no intended functionality change
Merge pull request #849 from sgraham/set-err-canon-components

set *err when too many components in CanonicalizePath
Merge pull request #850 from sgraham/ocd

whitespace/comment/wrap fixes, no intended functionality change
Remove unused variables.
Merge pull request #851 from nico/cleanup

Remove unused variables.
Make sure configure.py and ninja.cc always agree on if -t browse is included.

No behavior change on most platforms. On solaris, -t browse was compiled in
in ninja.cc but browse.cc wasn't compiled in, which probably means that building
on Solaris didn't work. It might be better now.

This also makes browse.cc automatically not included in bootstrap builds;
previously this was done manually through the NINJA_BOOTSTRAP check.
Merge pull request #852 from nico/browse

Make sure configure.py and ninja.cc always agree on if -t browse is incl...
Merge pull request #842 from nico/solaris

Fix building on Solaris.