fix https://github.com/evernote/evernote-cloud-sdk-ios/issues/15

Change-Id: If6b9347faaba3f361722cb9ad1d151905b29bb63
Add assertion to ensure ENSDKResources.bundle are loaded

Change-Id: I95642af17d264656956cbe95bff85365fb910e28
Add cancel method on ENNoteStoreClient

Change-Id: I4622505c6babc69c17c82c319d3cb46889bd70bf
Fix searching joined public notebooks

Change-Id: If01bf36b62c597a0a1cd3e3e6151421bb4178454
Support PDF display
Improve PDF display support
fix css button color