This fix add inline support for middleware/hosts so that
it is possible to specify hosts file insides the Corefile:
```
hosts inline example.org {
10.0.0.1 example.org
fallthrough
}
```
This fix fixes 999.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
* Rename middleware to plugin
first pass; mostly used 'sed', few spots where I manually changed
text.
This still builds a coredns binary.
* fmt error
* Rename AddMiddleware to AddPlugin
* Readd AddMiddleware to remain backwards compat
