Changes

Fix Bug 757: Regression of URL to URI conversion (Encoded path not compatible w/ file scheme.

Regression of (Bug 683, Commit b98825eb7cfb61aead4a7dff57471cd2d2c26823).

The URI encoded path cannot be read by File I/O (if file scheme), since the latter
requests an UTF8/16 name, not an URI encoded name (i.e. %20 for space).

The encoded URL is produced if calling 'uri.toURL()' and hence
the new 'IOUtil.toURL(URI)' provides a custom conversion recovering the UTF name via 'new File(uri).getPath()'.

Tested w/
  - synthetic URI/URL coposition (unit test)
  - manual w/ moving 'build' to 'build öä lala' for gluegen, joal and jogl.

+++

Misc.:

- 'URI JarUtil.getURIDirname(URI)'  -> 'URI IOUtil.getDirname(URI)'

++

Fix URLCompositionTest for Bug 757: If file, replace '/' in expected result w/ OS specific File.separatorChar

Fix URLCompositionTest for Bug 757 (2): If file, replace '/' in expected result w/ OS specific File.separatorChar

The JAR entry shall stay untouched, i.e. separator is platform independent '/'.

Fix URLCompositionTest for Bug 757 (3): If file, replace '/' in expected result w/ OS specific File.separatorChar

Take 3 (duh!): JRE impl. varies .. i.e. plain URL w/o JAR path differs from URL w/ JAR scheme on Windows .. well.