Otc: Add 'tcbdbtune' support and create 'large' databases

See: ARAKOON-373
See: http://jira.incubaid.com/browse/ARAKOON-373
Use @Incubaid/tokyocabinet vendor branch

Due to the need of some patches to TokyoCabinet, we no longer bundle
a TokyoCabinet source tarball in this repository, but track our vendor
branch as a submodule instead.

This commit adds the submodule and changes build files accordingly.
Track and expose TokyoCabinet submodule build revision
Update TokyoCabinet submodule to latest revision in ARAKOON-373

$ git shortlog 2cb5eb382..079426312
Nicolas Trangez (5):
    Add .gitignore
    CI: Add Jenkins scripts
    Add TCEOVERFLOW error code
    Add truncation/overflow checks & reporting
    TCHDB: Fixup 32bit overflows

See: https://github.com/Incubaid/tokyocabinet/compare/2cb5eb382...079426312
Update tokyocabinet submodule to latest upstream version
Merge pull request #38 from Incubaid/ARAKOON-373

Fix 'Invalid record header'