package/mongodb: new package

Here is the list of the changes compared to the removed mongodb 3.3.4
version:
- Remove patch (not applicable anymore)
- Add patch (sent upstream) to fix openssl build with gcc 7 and
  -fpermissive
- Remove 32 bits x86 platforms, removed since version 3.4:
  https://docs.mongodb.com/manual/installation/#supported-platforms
- Change license: since October 2018, license is SSPL:
  - https://www.mongodb.com/community/licensing
  - https://jira.mongodb.org/browse/SERVER-38767
- gcc must be at least 5.3 so add a dependency on gcc >= 6
- Add a dependency on host-python-xxx modules:
  https://github.com/mongodb/mongo/blob/r4.0.6/docs/building.md


- Use system versions of boost, pcre, snappy, sqlite, yaml-cpp and zlib
  instead of embedded mongodb ones
- Add hash for license files

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Tested-by: Adam Duskett <aduskett@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>