Renamed `copy()` to `copyAll()`
Added `copy(srcDir, srcFile, destDir, destFile)` function
Fixed #44 `mavenoverrides` default option is in the wrong config file section
Added `isFalse()` function for ceylon/ceylon-compiler#1759
Mkae sure `applyCwd()` doesn't add unnecessary `./` to the start of a file
Changed `sameFile()` to use the NIO `File.isSameFile()` method
Added `containsFile(files, file)` (basically for ceylon/ceylon-js#389)