[phobos] phobos commit, revision 1961

[dsource.org]

phobos commit, revision 1961


user: rsinfu

msg:
std.conv: enh 4518 (diagnostic)

- Improved the error message of enum->string conversion failure to report the actual value encountered.
- Cleaned up the impl. of enum<->string converters with EnumMembers.

http://www.dsource.org/projects/phobos/changeset/1961