beginswith, endswith accept Chars
Fix some issues related to eigvals

- Pass arguments to eigvals to eigvals!, so that eigvals(A, irange)
  and eigvals(A, vl, vu) work as described in the docs
- Restrict eigvals!/eigfact! to real symmetric/Hermitian or complex
  Hermitian matrices. Previously we allowed these methods to be called
  on complex symmetric matrices, which did not give correct results.
Introduce RealHermSymComplexHerm typealias and use where applicable
Triangular: fix error in BLAS.trmm call
Merge pull request #6830 from simonbyrne/triangular

Triangular: fix error in BLAS.trmm call
fix ambiguity warnings
type inference efficiency improvement

less use of () as a special argument value, and less unnecessary work
on ANY slots
Merge pull request #6832 from simonbyrne/triangular

fix ambiguity warnings
a few more precompiles
update helpdb
Merge pull request #6812 from JuliaLang/sjk/eig

Fix some issues related to eigvals
Merge pull request #6779 from WestleyArgentum/master

beginswith, endswith accept Chars
update docs for string functions that accept `Chars`
remove vestigial -T option
add -i option. fixes #6765