New Elements

• Added the CWIGGLER element, which uses a canonically-integrated wiggler code for general wiggler fields. This code was provided by Ying Wu of Duke University.
• Added the RFTM110 element, which provides simulation of a TM110 deflecting cavity, using a sixth-order expansion in $k\rho$, where $k$ is the radial wavenumber and $\rho$ is the radius.