hg: improve untracked files detection (speed)
hg: refactor outgoing commits counting

Rename variable 'has_commit' to 'commits' and declare it as integer.
hg: improve speed of check for uncommitted stuff
hg: minor code layout
hg: remove usage of tail+awk in favor of sed
Merge branch 'refactor/hg-cleanup' into develop

Cleanup _lp_hg_branch_color implementation for improved speed.
Quote $LP_MARK_DEFAULT to avoid problem with space.
Rename misnamed local variable.
Respect the _lp_battery API.
Replace "pmset -g batt" parsing.
Reduce the verbosity of git calls.
has_commit is an integer.
fixing the untracked flag being always up
replacing replacing "git status" option "--short" by "--porcelain"

The behavior of porcelain seems more adapted to the liquidprompt usage

From the "git status" documentation :

The porcelain format is similar to the short format, but is guaranteed
not to change in a backwards-incompatible way between git versions or
based on user configuration. This makes it ideal for parsing by scripts.
The description of the short format above also describes the porcelain
format, with a few exceptions:

1. The user’s color.status configuration is not respected;
   color will always be off.
[...]
Save IFS at startup to restore it in _lp_set_prompt

We already restore IFS to its default value. This patch only changes the
way it is done to avoid a call to 'echo' in a sub-shell at runtime.
Fixes #267.
"hg outgoing" is slow, so diabled. closes #217
Correct the analog hour calculation.

 "date %I" returns a number between 1 and 12 and we want 12 to be 0.
RUNTIME: minor optimization
Replace over use of grep/cut with sed or awk, globally reduce number of fossil call
Forgot one _lp_escape