doc: fix link to basic concepts

Add comments on app_mode with possible values

Add note about phantomjs binary and PNG rendering.

feat(influxdb): More alias options, can now use  syntax to reference part of a measurement name (seperated by dots), closes #2599

fix(graph tooltip): fixed graph tooltip when stacking and one series is not stacked (via override), fixes #2670

doc: fix link to basic concepts

fix(influxdb): Fixed issue when using the eye to disable queries in the query editor and when applying aliases, #2651

Iterate over the right env override list variable

fix(inspector): lots of improvements and fixes for the error inspector, now shows you request details and responses in many more cases, fixes #2646

fix(influxdb): fixes and refactorings of influxdb 0.9 editor, no longer shows template vars in keys dropdown and group by dropdownm, fixes #2636

influxdb doc: typo fixed

fix(graph tooltip): multi series tooltip did no highlight correct point when stacking was enabled and series were of different resolution, fixes #2620