fix issue 9959 - Add functional pattern matching for object references

Add the function std.algorithm.castSwitch, which chooses a delegate
based on the class of an object and run that delegate with that object.
Add std.range.enumerate

Fixes issue 5550
Make std.file.getAttributes safe
Tweak static if in Array

Probably changes nothing in the generated code, but can have an impact of attribute inference. I'm trying to get this to be `@nogc`
std.process: Update unittest_burnin to test new functions
std.process: Test random characters at filename start as well
std.math: added frexp for float and double
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.
Split up the intertwined mess of std.regex.

The docs and API still stay in one file.
With time and refactoring more internals may be
exposed such as parser, each engine explicitly
and the sample generator (generator.d).

Also inclusdes changes prompted by reviews/pulls:

Convert spaces-->tabs in makefiles.
Move things (again) to std/regex/internal.
Use new package(std.regex) feature.
Remove C-style arrays (some other pull against regex.d).
Merge pull request #2498 from monarchdodra/ArrayStaticIf

Tweak static if in Array
Merge pull request #2412 from DmitryOlshansky/regex-pkg

Split up the intertwined mess of std.regex.
Fix Windows makefiles' install target
Merge pull request #2515 from CyberShadow/pull-20140915-162306

Fix Windows makefiles' install target
Merge pull request #2496 from tom-tan/safe-file-getAttributes

Make std.file.getAttributes safe
Make std.file.getLinkAttributes safe
Mark std.file.isDir and its unittest as safe
Merge pull request #2517 from tom-tan/safe-file-isDir

Mark std.file.isDir and its unittest as safe
Merge pull request #2516 from tom-tan/safe-file-getLinkAttributes

Make std.file.getLinkAttributes safe
Mark unittests for std.file.attrIsDir and attrIsFile as safe