Update README.md
Merge pull request #1 from nemomobile/vdv-devel

[buteo-sync-plugins-email] Initial code.
Fix pro file.
Merge pull request #2 from nemomobile/vdv-devel

[buteo-sync-plugins-email] Report sync failures.
[buteo-sync-plugins-email] Use emailAgent singleton curretly.

Update dependencies.
[buteo-sync-plugins-email] Use own instance of EmailAgent
[buteo-sync-plugins-email] Sync online accounts managed by Buteo.