fix #3672, dispatch bug due to type intersection

the improved typeintersect revealed a bunch of ambiguity warnings,
which could be fixed up by improving method specificity a bit, and
manually patching one case.
Manually symlink libopenblas.so to libopenblas.so.0 in usr/lib/
Update OS X build instructions in README.
Return sum of squared residuals from gglse
document SymTridiagonal, improve other tridiagonal docs
more helpful error messages in ccall and cglobal
cleanup UV objects, especially status codes. fixes #1923. fixes #3676
on uv close, notify all waiting tasks
fix @assert for use during sysimg build, and use it
fix #3544
fix small TODO in quadgk (use SymTridiagonal eigensolver)
Fail earlier if FD is already being watched
fix serious codegen bug in struct construction
fix deprecation of start_timer
Updated info in README.md

* CentOS 5 building with gcc44
* Ubuntu PPAs
* Troubleshooting table
* Removed Rmath reference
fix warning in timer callback hook
fix #1768
stringify at runtime instead of using try in assert macro
Consolidate connect methods & add tests
Fix bugs uncovered by last commit

Also consistently use malloc instead of jl_alloca in fs.jl
fix #3687