Support for gather* environment

[chronos1970]

Description

The LaTeX gather* multi-line environment is not recognized as an environment while gather, align and align* work as expected.

Steps to Reproduce

1. Visit the MathLive Demo
2. Type the following in the LaTeX field

\begin{gather*}x \\ x^2 \\ x^3 \end{gather*}

Actual Behavior

Expected Behavior

The output should be the same as using the gather environment

Environment

Is this a regression: did it use to work in a previous version?

I don't think this ever worked before.

MathLive version: 0.98.5

Operating System: Windows 10

Browser: Firefox