Initial implementation of a safe (no fatalErrors thrown) OutputStream.

[tonystone]

The current implementation (as of this writing) of FileHandle in swift will call fatalError() for any thrown error during the write operation.

    public func write(_ data: Data) {
        data.enumerateBytes() { (bytes, range, stop) in
            do {
                try NSData.writeToFileDescriptor(self._fd, path: nil, buf: UnsafePointer<Void>(bytes.baseAddress!), length: bytes.count)
            } catch {
                fatalError("Write failure")
            }
        }
    }

TraceLog must be reliable and not have cases that will crash the app so we were compelled to write our own FileOutputStream class to replace the FileHandle foundation class. This also gives us the advantage of improved performance during writes.

See: https://bugs.swift.org/browse/SR-2138 for more information.

[codecov]

Codecov Report

Merging #75 into release-5.0 will decrease coverage by 0.25%.
The diff coverage is 96.42%.

@@               Coverage Diff               @@
##           release-5.0      #75      +/-   ##
===============================================
- Coverage        99.13%   98.88%   -0.26%     
===============================================
  Files               22       23       +1     
  Lines              578      625      +47     
===============================================
+ Hits               573      618      +45     
- Misses               5        7       +2

Impacted Files	Coverage Δ
.../TraceLog/Utilities/Streams/FileOutputStream.swift	100% <100%> (ø)
Sources/TraceLog/Writers/FileWriter.swift	100% <100%> (ø)	⬆️
Sources/TraceLog/Writers/ConsoleWriter.swift	100% <100%> (ø)	⬆️
...es/TraceLog/Utilities/Streams/StandardStream.swift	50% <50%> (ø)

[codecov]

Codecov Report

Merging #75 into release-5.0 will increase coverage by 0.86%.
The diff coverage is 100%.

@@              Coverage Diff              @@
##           release-5.0    #75      +/-   ##
=============================================
+ Coverage        99.13%   100%   +0.86%     
=============================================
  Files               22     26       +4     
  Lines              578    711     +133     
=============================================
+ Hits               573    711     +138     
+ Misses               5      0       -5

Impacted Files	Coverage Δ
.../TraceLog/Utilities/Streams/FileOutputStream.swift	100% <100%> (ø)
...es/TraceLog/Utilities/Streams/StandardStream.swift	100% <100%> (ø)
...og/Utilities/Streams/OutputStreamError+Posix.swift	100% <100%> (ø)
Sources/TraceLog/Writers/ConsoleWriter.swift	100% <100%> (ø)	⬆️
...tilities/Streams/FileOutputStreamError+Posix.swift	100% <100%> (ø)
Sources/TraceLog/Writers/FileWriter.swift	100% <100%> (ø)	⬆️
... and 3 more