Grammar and spelling fixes.

[metaperl]

Before submitting a pull request, please make sure the following is done:

1. Fork the repository and create your branch from master.

2. Run the build.py and test.py scripts.

3. If you are fixing something, add tests that fail in the current version and pass in yours.

4. If you're developing a new feature open an issue first to discuss it. Some features may be useful to you but harmful to others be it because of performance, new dependencies or different perspectives.

5. One more time: Don't forget to add tests.

6. Ensure the entire test suite is passing and overall performance is not degraded.