Bruyere

Main differences in "bruyere" and "master" are 

* Different handling of LHS. 
   - If possible, evaluation will happen as in master, but with `__LHS` replaced by `<the expresson>`. This will preserve the call, which gives better behavior e.g. using formula interfaced functions (lm, glm, etc), and when the call is used to generate labels, e.g. in plot.
   - If the above is not possible, which happens when lhs cannot be treated as a call or name, then `__LHS` is used as name in the evaluation of the lhs. An example is `iris %>% dplyr::filter(Species %>% substr(1, 1) == "v")`. The same is not the case if using `iris %>% subset(Species %>% substr(1, 1) == "v")`.
* Data manipulation/filtering functions have been removed to keep the aim and scope of magrittr very specific. Instead a variety of aliases have been added for operations such as multiplication, addition, etc.
* Examples in the readme have been updated to reflect the changes.