Revert "Throw exception in 1.8 mode for empty string"

This reverts commit 325aa84a6be9ecd3602c009597b59a9ded5477c1.
Revert "Always force eAscii as encoding for symbols in 1.8"

This reverts commit 4338798162fbe00accfadcbdceb6c26699ef7e09.
Revert "Remove tags for passing specs"

This reverts commit cc14fb8737aeb454b52e14662cbc8bdffc034776.
Revert "Add encoding support for Symbol"

This reverts commit 239ce0c6c00401b8111342fafa55dab80c13ded5.

There are some weird issues when building with 1.9 / 2.0 that need to be
investigated first.