Bar charts fail if a series name is null

[David Platten]

sorting.js doesn't check for a null name. If there is a null name then it fails and charts never appear.

[David Platten]

Fixed error that caused charts to fail if a bar chart series was null [skip ci]. References issue #633

→ <<cset d7de7992602e>>

[Ed McDonagh]

Merged in issu3633BarChartFailIfNameNull (pull request #196)

Fixed error that caused charts to fail if a bar chart series was null [skip ci]. Fixes issue #633

→ <<cset 6e19c7743dce>>