Document Error and its constructor
Add ENOTSUP for linux, which maps to EOPNOTSUPP

glibc aliases ENOTSUP to EOPNOTSUPP. We therefore should declare it as well
as EOPNOTSUPP.
demangle @nogc
Mark first param of apply functions as 'in'
Add unittests from _aApplyR.d
Merge pull request #769 from dsp/linux/ENOTSUP

Add ENOTSUP for linux, which maps to EOPNOTSUPP
replace some redeclaration with the respective imports
Merge pull request #771 from ibuclaw/inparm

Mark first param of apply functions as 'in'
Merge pull request #770 from WalterBright/demangle_nogc

demangle @nogc
Merge pull request #765 from ntrel/doc-Error

Document Error and its constructor
Replace implicit catches of Throwables with explicit catches.
Merge pull request #772 from AndrejMitrovic/RemoveImplicitCatch

Replace implicit catches of Throwables with explicit catches.
Merge pull request #751 from rainers/cleanup_gc

[refactor] replace some redeclaration with the respective imports in gc.d