take advantage of ::None for identifying unreachable code
Merge branch 'master' of github.com:JuliaLang/julia
rename backtrace() to catch_backtrace(), since it gives the backtrace
of the error you caught in the current catch block

make backtrace() give a trace from where it is called

expose the function that maps code addresses to source location info

closes #1952
Merge branch 'master' of github.com:JuliaLang/julia
fix most of the problems in #2590
close #2590
add prepend!. closes #1854
Update the linalg documentation
Linear algebra documentation has its own file.
Make linalg docs come out right in the manual (rst tweaking)
Update index.
Some renamings for consistency as discussed in #2593.

Eigen -> EigenDense
eigenfact -> eigfact
Hessenberg -> HessenbergDense

Includes doc updates for linalg as well.
Separate sparse matrix documentation into a separate file.
Add sparse.rst, which I forgot to add in the last commit.
Allow overriding LLVM Targets
Avoid using bool() in the call to nnz.
bool(Complex) gives InexactError, which causes a whole bunch of stuff to break
Also add a test for sparse complex matrix construction.
Merge branch 'master' of github.com:JuliaLang/julia
Some updates to the laplace benchmark.
Remove old median example.
correct sprintf/printf doc