[dev] dwm bit fields conversion

[koneu]

In Xdefs.h, Bool is typedef'd as int (= at least 2 bytes, sometimes more, 
depending on the implementation), of which we set the last bit to 1 or 0.
In the Monitor and Client structures dwm uses, we can instead use char bit 
fields, storing up to 8 Bool values in 1 byte.

diff --git a/dwm.c b/dwm.c
index 314adf4..83af1f6 100644
--- a/dwm.c
+++ b/dwm.c
@@ -91,7 +91,7 @@ struct Client {
        int basew, baseh, incw, inch, maxw, maxh, minw, minh;
        int bw, oldbw;
        unsigned int tags;
-       Bool isfixed, isfloating, isurgent, neverfocus, oldstate, isfullscreen;
+       unsigned char isfixed :1, isfloating :1, isurgent :1, neverfocus :1, 
oldstate :1, isfullscreen :1, :2;
        Client *next;
        Client *snext;
        Monitor *mon;
@@ -121,8 +121,7 @@ struct Monitor {
        unsigned int seltags;
        unsigned int sellt;
        unsigned int tagset[2];
-       Bool showbar;
-       Bool topbar;
+       unsigned char showbar :1, topbar :1, :6;
        Client *clients;
        Client *sel;
        Client *stack;