Add syntax highlighting to boadcast function

[driesbenoit]

Proper syntax highlighting for broadcast function (currently dot-syntax is not recognized as function name), e.g.:

occursin.(r"^[0-9]",df[:Result])
.![true,false]

Note, in order to see these changes, you have to enable function and operator highlighting. This can be done, for example, by creating a file ~/.vim/after/syntax/julia.vim containing the following lines:

" Highlight function
:hi link juliaFunctionCall Identifier
" Highlight Operators in red
:hi Operator guifg=Red ctermfg=Red

[carlobaldassi]

Thanks for pointing this out, I fixed both issues in an alternative way (272935f6c2c7b01278756735c2d6fff5e5b65553 and f4cdfd5f8a90ee45ba2051b1148fab141d6299cb).