Add lodash dependency.

Additionally, stop listing *.min.js library dependencies in all scripts except
for main.js. Since main.js loads them first, everyone else can simply assume
they're already present.
Remove Votr.merge(), and use buildUrl() implicitly in Link and navigate().
Add an initial version of the main menu.
Add ajax.js.
Add ZapisnyListSelector, with proof-of-concept MojeSkuskyPage.
Define actions centrally instead of each file adding its own entries.
Replace @require with automatic dependencies based on Votr.* usage.