Speedup by checking the page only when necessary; Logging update.

[mfalesni]

Basically, up until now widgetastic executed the ensure_page_safe before EVERY element lookup. Now it does it only if it hits an error.

Also added some post-action ensure_page_safe calls. That should reduce the incidence of the repeated lookup.

• some logging improvements and touches here and there ...

Ran some automation with this branch and it worked well.

This should probably become V0.7.0

[coveralls]

Coverage increased (+0.03%) to 86.456% when pulling 7743689 on faster-interactions into d0a8a8c on master.

[psav]

First pass looks good

[coveralls]

Coverage increased (+0.4%) to 86.871% when pulling a2fc752 on faster-interactions into d0a8a8c on master.

[coveralls]

Coverage increased (+0.3%) to 86.762% when pulling 7d7a4e6 on faster-interactions into d0a8a8c on master.

[coveralls]

Coverage increased (+0.4%) to 86.78% when pulling b9a8689 on faster-interactions into d0a8a8c on master.

[coveralls]

Coverage increased (+0.4%) to 86.78% when pulling 351196e on faster-interactions into d0a8a8c on master.