#113 add first version of new GUI
#113 fix button sizes and spacing
#36 preview generated data of up to four features
* no feature names, yet
#36 fix failing test
#113 remove unused variable
#113 center frame
#117 move progress bar updating and thread interruption to DataGeneratorService
* number of instances are generated in batches
* export connection has to be closed manually after all batches are complete
#116 remove checked exceptions from ExportConnection interface method signatures
#113 adjust focus traversal order
#114 remove separators
#114 avoid resizing of the top panel elements
Merge branch 'master' into v0.2.2gui
Merge branch 'master' into v0.2.2gui

Conflicts:
	src/main/java/de/frosner/datagenerator/gui/main/ProgressBarManager.java
#112 document PreviewTableManager
#112 document TextAreaLogger
Merge branch 'master' into v0.2.2gui

Conflicts:
	src/main/java/de/frosner/datagenerator/export/CsvExportConnection.java
	src/main/java/de/frosner/datagenerator/export/ExportConnection.java
	src/test/java/de/frosner/datagenerator/export/CsvExportConnectionTest.java
	src/test/java/de/frosner/datagenerator/generator/DataGeneratorTest.java
Merge branch 'master' into v0.2.2gui
* resolve rename conflict
Merge branch 'master' into v0.2.2gui
Merge branch 'master' into v0.2.2gui

Conflicts:
	src/main/java/de/frosner/datagenerator/export/CsvExportConnection.java
Merge branch 'master' into v0.2.2gui

Conflicts:
	src/main/java/de/frosner/datagenerator/export/ExportConnection.java
	src/main/java/de/frosner/datagenerator/generator/DataGenerator.java
	src/test/java/de/frosner/datagenerator/generator/DataGeneratorIntegrationTest.java