[ARM] Implement parse!real for systems with 64bit reals

and some unittest fixes
Fix formatting in std.conv.parse!real
Tweak zip implementation

Made doc location consistent in regards to static ifs.
Merge pull request #1896 from monarchdodra/zipTweak

Tweak zip implementation
Merge pull request #1862 from jpf91/arm-4

[ARM] Implement parse!real for systems with 64bit reals