Plots.jl increase spacing along axes

[rafael.guerra]

For 1., use plot() keyword bar_width.
For 2., use xticks.

Example:

using Plots; gr()
x, y = 'a':'z', rand(1:10, 26)
bar(x, y, xticks=(0.5:length(x)-0.5, x), xtickfontsize=5, bar_width=0.5, widen=false)