Add std.range.enumerate

Fixes issue 5550
std.process: Update unittest_burnin to test new functions
std.process: Test random characters at filename start as well
fix Issue 13446 - Can't use executeShell/escapeShellFileName to redirect to file whose name starts with &

Discovered and verified by -version=unittest_burnin
fix Issue 13450 - Add WindowsException and wenforce to std.exception

Also expose ErrnoException's errno field as a documented property
for consistency.
Make std.file.isFile, isSymlink and their unittests safe
Range adaptor: cache

As discussed in this thread:
http://forum.dlang.org/thread/ovbjcmogezbvsxrwfcol@forum.dlang.org

This provides a range adaptor that cache the result of another range.

Meant as a lazy alternative to array. Not much else to say...?

Documentation might suck.
Fix trustedSymlink to use toStringz
Fix issue 13483 std.range.tee should accept function symbols
Document signature of function to be passed to recurrence().
Use ddoc'd unittest instead of inline code of questionable workability.
fix Issue 13477 - std.process should ignore unnamed service variables on Windows
Show examples for each possible function form.
Merge pull request #2531 from quickfur/issue9535

Document expected function signature in std.range.recurrence
issue8851

some more

some review fixes

some more

removed a to
Merge pull request #2533 from burner/issue8851

issue8851
findRoot optimization

restore signbit check

findRoot style update

findRoot style update 2
Merge pull request #2524 from 9il/ctfe-math-2

findRoot optimization and bugfix
Improve documentation of std.string.column.
Merge pull request #2514 from CyberShadow/pull-20140915-022527

fix Issue 13477 - std.process should ignore unnamed service variables on Windows