clang-format: update config to 3.5

Fixes in this update:
- const not on single line
- curlys in try/catch same as if/else
- function declaration indented if broken after type
- initializer list begins always on new line
- break statement on own line
Merge pull request #185 from toxeus/clang3.5

clang-format: update to 3.5
OTSymmetricKey Password Scope Check
Merge pull request #187 from yamamushi/develop

OTSymmetricKey Password Scope Check
OTIdentifier: Remove link to OTOffer
OTIdentifier: Remove link to OTMarket
OTTransactions: Remove link to OTTrade
Merge pull request #180 from lclc/otidentifier

Decouple trading from core
Moved agreement and payment plan out into subdir.
Merge pull request #188 from murrekatt/develop

Moved agreement and payment plan out into subdir.
CMake: check ZMQ version
Merge pull request #190 from toxeus/zmqVersionCheck

CMake: check ZMQ version
Doxygen: fix input paths

Some interesting stuff was missing previously (MessageProcessor for instance)
CMakeLists: fix indentation of BUILD_DOCUMENTATION
Doxygen: add some options for Doxyfile generation

`make doc` now creates collaboration and inheritance graphs by default

Run cmake with -DDOC_GRAPHS=No to disable all graphs and run use
-DDOCS_FULLGRAPHS=Yes to also generate call/callee graphs (large)
Doxygen: add css tweaks

Remove the header. Vertical space is precious on laptops.
Merge pull request #192 from OttoAllmendinger/doxygen-tweaks

Doxygen tweaks
CMake: Generate opentxsConfig.cmake so we can use find_package in server and other applications that use the opentxs library