Merge pull request #236 from morphonets/fix-save-swc

Fix SWC saving from API

src/main/java/sc/fiji/snt/Tree.java

@@ -1683,7 +1683,7 @@ private static File getFile(final String filename, final boolean checkIfAvailabl
 			f = new File(filename.replaceFirst("^~", System.getProperty("user.home")));
 		else
 			f = new File(filename);
-		if (!SNTUtils.fileAvailable(f))
+		if (checkIfAvailable && !SNTUtils.fileAvailable(f))
 			throw new IllegalArgumentException("File is not available: " + filename);
 		return f;
 	}