Feature #481 - color should follow rc order

- Added feature #481, allowing for user control of the color rule order
  of precedence via the 'rule.precedence.color' configuration variable.
- Color rules now obey the rc.search.case.sensitive configuration option.
- The color.keyword.XXX color rule now applies to annotations too.

doc/man/task-color.5

@@ -236,6 +236,20 @@ It is possible to create a very colorful mix of rules.  With 256-color support,
 those colors can be made subtle, and complementary, but without care, this can
 be a visual mess.  Beware!
 
+The precedence for the color rules is determined by the configuration variable
+'rule.precedence.color', which by default contains:
+
+    due.today,active,blocked,overdue,due,keyword,project,tag,recurring,pri,tagged
+
+These are just the color rules with the 'color.' prefix removed.  The rule
+'color.due.today' is the highest precedence, and 'color.tagged' is the lowest.
+
+The keyword rule shown here as 'keyword' corresponds to a wildcard pattern,
+meaning 'color.keyword.*', or in other words all the keyword rules.  Similarly
+for the 'color.tag.*' and 'color.project.*' rules.
+
+There is also 'color.project.none', 'color.tag.none' and 'color.pri.none'.
+
 .SH THEMES
 Taskwarrior supports themes.  What this really means is that with the ability to
 include other files into the .taskrc file, different sets of color rules can
@@ -266,6 +280,10 @@ dark-green-256.theme
 dark-blue-256.theme
 .RE
 
+You can also see how the theme will color the various tasks with the command:
+
+    $ task color legend
+
 Better yet, create your own, and share it.  We will gladly host the theme file
 on <http://taskwarrior.org>.
 

doc/man/taskrc.5

@@ -536,40 +536,50 @@ terminal, can be obtained by running the command:
 .B task color
 .RE
 
+
 .RS
-The coloration rules and their defaults are:
+The coloration rules are:
 .RE
 
 .RS
-.B color.overdue=bold red
-The color for overdue tasks.
+.B color.due.today
+Task is due today
 .br
-.B color.due.today=bold magenta
-The color of tasks due today.
+.B color.active
+Task is started, therefore active.
 .br
-.B color.due=bold yellow
-The color of due tasks.
+.B color.blocked
+Task is blocked by a dependency.
 .br
-.B color.pri.H=bold
-The color of priority:H tasks.
+.B color.overdue
+Task is overdue (due some time prior to now).
 .br
-.B color.pri.M=on yellow
-The color of priority:M tasks.  No default value.
+.B color.due
+Task is coming due.
 .br
-.B color.pri.L=on green
-The color of priority:L tasks.  No default value.
+.B color.project.none
+Task does not have an assigned project.
 .br
-.B color.pri.none=white on blue
-The color of priority: tasks.  No default value.
+.B color.tag.none
+Task has no tags.
 .br
-.B color.active=bold cyan
-The color of active tasks.
+.B color.tagged
+Task has at least one tag.
 .br
-.B color.tagged=yellow
-The color of tagged tasks.
+.B color.recurring
+Task is recurring.
 .br
-.B color.recurring=on red
-The color for recurring tasks.
+.B color.pri.H
+Task has priority H.
+.br
+.B color.pri.M
+Task has priority M.
+.br
+.B color.pri.L
+Task has priority L.
+.br
+.B color.pri.none
+Task has no priority.
 .RE
 .RE
 
@@ -690,6 +700,15 @@ Colors used by the undo command, to indicate the values both before and after
 a change that is to be reverted.
 .RE
 
+.TP
+.B rule.precedence.color=overdue,tag,project,keyword,active,...
+.RS
+This setting specifies the precedence of the color rules, from highest to
+lowest.  Note that the prefix 'color.' is omitted (for brevity), and that any
+wildcard values (color.tag.XXX) is shortened to 'tag', which places all specific
+tag rules at the same precedence, again for brevity.
+.RE
+
 .SS SHADOW FILE
 
 .TP