Refactor. Tree node can contain several metrics now
Implemented rule to unite many metrics under single node in control tree
Temp commit to switch to other branch
Refactor - removed unnecessary parameter taskIds from PlotDataProvider interface
Refactor - now every MetricNameDto knows where it comes from = where to take values
Plots can be fetched for MetricNodes => one plot with several metrics (lines)
Partially working solution (not finished)
All plots are fetched / removed by MetricNode => single MetricNode = single plot in Metric tab
+ create TestInfoService
+ add ability to fetch testInfo for all chosen tests in one call
code cleaning
before merge with master
merge with master
clean code, fixed bugs in gwt-servlet and CommonDataProvider
JFG-620 Create backend for tags
Merge https://github.com/griddynamics/jagger into JFG-620

Conflicts:
	webclient/src/main/java/com/griddynamics/jagger/webclient/client/SessionDataService.java
	webclient/src/main/java/com/griddynamics/jagger/webclient/client/SessionDataServiceAsync.java
	webclient/src/main/java/com/griddynamics/jagger/webclient/client/components/SessionComparisonPanel.java
	webclient/src/main/java/com/griddynamics/jagger/webclient/client/components/TagBox.java
	webclient/src/main/java/com/griddynamics/jagger/webclient/client/data/WebClientProperties.java
	webclient/src/main/java/com/griddynamics/jagger/webclient/server/SessionDataServiceImpl.java
 + add check for null message in ExceptionPanel
 + create hierarchy for MetricDataFetching from database
     + standard metrics: throughput, duration, avg latency, samples, success rate
     + latency metrics: Latency %d %
     + stabs for custom metrics, and validators
 + add creating of latency metric name into static method
 + bug fix with TestInfoService
Merge branch 'JFG_637_metrics_on_single_node' of github.com:dlatnikov/jagger into webui-performance

Conflicts:
	webclient/src/main/java/com/griddynamics/jagger/webclient/client/PlotsServingBase.java
	webclient/src/main/webapp/WEB-INF/gwt-servlet.xml
Merge pull request #427 from dlatnikov/JFG_637_metrics_on_single_node

Jfg 637 group many metrics under single node of control tree
+ fetching metrics with batches
+ unsupportedException in CustomMetricPlotDataProvider
- remove one method (not used) from MetricDataService
+ code cleaning