Retool :Git blame colored commits

Use 3 characters of the commit hash rather than 6, limiting the maximum
total declarations to 4,096 rather than 16 million. Avoid color
components lower than 0x20 and higher than 0xdf to help avoid colors
that blend into the background, light or dark.  And for the terminal,
replace the use of CSApprox with a simple usage of the 6x6x6 color cube
found on 256 color terminals.  CSApprox aims to provide accurate
replication of the input colors, whereas our goal is simply to use all
colors in roughly equal amounts.

doc/fugitive.txt

@@ -59,6 +59,12 @@ that are part of Git repositories).
                         ~     reblame at [count]th first grandparent
                         P     reblame at [count]th parent (like HEAD^[count])
 
+                                                *g:fugitive_dynamic_colors*
+                        In the GUI or a 256 color terminal, commit hashes will
+                        highlighted in different colors. To disable this:
+>
+                        let g:fugitive_dynamic_colors = 0
+<
 :[range]Git blame [...] If a range is given, just that part of the file will
 :Git blame [...] {file} be blamed, and a horizontal split without
                         scrollbinding is used.  You can also give an arbitrary