Jermolene/TiddlyWiki5 — pull request #555 by pmario (2014-04-14 18:34:22+00:00)
Title: fixes a problem with the --savetiddler command, 

it the tiddler doesn't exist and adds a propper error message

to reproduce
```
node $(TIDDLYWIKI5_DIR)/tiddlywiki.js \
editions \
--verbose \
--rendertiddler $:/core/save/all $(DEV_DIR)/index.html text/plain \
--savetiddler $:/XXXXXXXXXXxxfavicon.ico $(DEV_DIR)/favicon.ico \
|| exit 1
```
The XXXXfavicon tiddler will cause a stack trace error, which doesn't help. I did add a check and a propper message, that tells the user, what to do .