Added new illustrations

map-reduce illustration
secondary-indexes illustration (ruby/python/js)
data-modeling illustration
table-join illustration
Merge pull request #413 from rethinkdb/josh/illustrations

Added new illustrations
Edit language for 'filter'. Closes #423
Expand and/or API docs; closes #434
Update MapReduce article; closes #421
Clarify skipped semantics; closes #290
Fix typos in iso8601 API docs
Fix a few typos; closes #436
Reformat some API example code; fixes #234
Fixes #426
Merge branch 'issue-426-defaulttime'
Add importing document

Fixes #417
Merge branch 'issue-417-importing'
Change defaultTimezone in Javascript index file
Change "upsert" to "conflict"
Add other languages; fixes #424
Document array_limit; closes #433
Merge branch 'v1.14' of github.com:rethinkdb/docs into v1.14