Initial release

A similar library oeis already existed, but there is the following problems:

1. The key of HashMap is not instance of Eq.
2. The values of Maple and Mathematica are swaped.
3. Although OEIS provides JSON, it uses line-keyd ASCII.
4. HTTPS is not supported.
5. Cannot receive multiple search results (only the 1st result).
6. Many search prefixes are provides, but only id: and seq: can be used.
7. And each function is separate for each Prefix.

First, I sent a few lines pull requests to solve 1, 2.
The request has merged to master of oeis.

After that, I noticed problems from 3..7.
I thought it is hard to fix all of these only with pull request.
So, I have make a new library, and solved all problems of 3..7.

Added

• Make possible to get all search results.
• Support all search prefixes in here.
  • Make possible to give each Prefix by data constructor of SearchStatus.

Changed

• Make to use JSON by OEIS.
• Support HTTPS.