Standard/Classic/UAX tokenizers could be more ram efficient [LUCENE-6913]

These tokenizers map codepoints to character classes with the following datastructure (loaded in clinit):

```
private static char [] zzUnpackCMap(String packed) {
char [] map = new char[0x110000];
```

This requires 2MB RAM for each tokenizer class (in trunk 6MB if all 3 classes are loaded, in branch_5x 10MB since there are 2 additional backwards compat classes).

On the other hand, none of our tokenizers actually use a huge number of character classes, so `char` is overkill: e.g. this map can safely be a byte [] and we can save half the memory. Perhaps it could make these tokenizers faster too.

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Migrated from [LUCENE-6913](https://issues.apache.org/jira/browse/LUCENE-6913) by Robert Muir (@rmuir), updated Aug 22 2016
Attachments: [LUCENE-6913.not.a.patch](https://apache.github.io/lucene-jira-archive/attachments/LUCENE-6913/LUCENE-6913.not.a.patch)