STONWriter produces invalid JSON when a string includes single quote characters.

[gcotelli]

To reproduce evaluate:
STON toJsonString: '''' and you will get "\'" instead of "'".

Something like the following should fix the problem:

STONWriter>>jsonMode: boolean

	jsonMode := boolean.
	jsonMode
		ifTrue: [
			STONCharacters
				at: $' codePoint + 1 put: #pass;
				at: $" codePoint + 1 put: '\"' ]
		ifFalse: [
			STONCharacters
				at: $" codePoint + 1 put: #pass;
				at: $' codePoint + 1 put: '\''' ]

Would be a good idea to add some test cases covering the handling of both single and double quotes for Smalltalk and JSON mode.

[dalehenrich]

I tried implementing your workaround but some of the existing STONWriterTests JSON tests started failing. I was hoping to include the fix in Rowan masterV2.3.2 for the 3.6.7 release, "at the last minute", but don't have the time (at this moment) to look into a better solution ... should be able to return to this before the end of the year ...