Summary:
The `--continue-analysis` option enables continuing analysis after more targets are captured by
`--continue`. For example,
```
$ infer capture -- buck build tgt1
$ infer analyze --merge
$ infer capture --continue -- bucck build tgt2
$ infer analyze --merge --continue-analyze
```
In the last analysis, it reuses the analysis results of `tgt1` from the previous analysis. If
`tgt1` and `tgt2` have a same dependency to a library, the analysis results of the library is also
reused.
Reviewed By: dulmarod
Differential Revision: D19996598
fbshipit-source-id: bb6874a6f