Set the maximum file limit for POSIX systems

[acronce]

• Resolves an issue I saw where the macOS application's dylibs could not be loaded because I had too many maps.
• Due to not so great error logging, this problem was non-obvious. Ultimately I managed to spot the error 24, which is means too many open files.
• On macOS the default number of open files is 256 (without this change).
• The Windows implementation currently does nothing, but that's reasonable because the limit is quite large (10k I think).