Add test for git binary diff support

tests/test-git-export

@@ -47,3 +47,16 b' hg diff --git -r 6:tip'
 
 echo '% nonexistent in tip+chmod'
 hg diff --git -r 5:6
+
+echo '% binary diff'
+cp $TESTDIR/binfile.bin .
+hg add binfile.bin
+hg diff --git > b.diff
+cat b.diff
+
+echo '% import binary diff'
+hg revert binfile.bin
+rm binfile.bin
+hg import -mfoo b.diff
+cmp binfile.bin $TESTDIR/binfile.bin
+

tests/test-git-export.out

@@ -44,3 +44,24 b' rename to dst'
 diff --git a/src b/src
 old mode 100644
 new mode 100755
+% binary diff
+diff --git a/binfile.bin b/binfile.bin
+new file mode 100644
+index 0000000000000000000000000000000000000000..37ba3d1c6f17137d9c5f5776fa040caf5fe73ff9
+GIT binary patch
+literal 593
+zc$@)I0<QguP)<h;3K|Lk000e1NJLTq000mG000mO0ssI2kdbIM00009a7bBm000XU
+z000XU0RWnu7ytkO2XskIMF-Uh9TW;VpMjwv0005-Nkl<ZD9@FWPs=e;7{<>W$NUkd
+zX$nnYLt$-$V!?uy+1V%`z&Eh=ah|duER<4|QWhju3gb^nF*8iYobxWG-qqXl=2~5M
+z*IoDB)sG^CfNuoBmqLTVU^<;@nwHP!1wrWd`{(mHo6VNXWtyh{alzqmsH*yYzpvLT
+zLdY<T=ks|woh-`&01!ej#(xbV1f|pI*=%;d-%F*E*X#ZH`4I%6SS+$EJDE&ct=8po
+ziN#{?_j|kD%Cd|oiqds`xm@;oJ-^?NG3Gdqrs?5u*zI;{nogxsx~^|Fn^Y?Gdc6<;
+zfMJ+iF1J`LMx&A2?dEwNW8ClebzPTbIh{@$hS6*`kH@1d%Lo7fA#}N1)oN7`gm$~V
+z+wDx#)OFqMcE{s!JN0-xhG8ItAjVkJwEcb`3WWlJfU2r?;Pd%dmR+q@mSri5q9_W-
+zaR2~ECX?B2w+zELozC0s*6Z~|QG^f{3I#<`?)Q7U-JZ|q5W;9Q8i_=pBuSzunx=U;
+z9C)5jBoYw9^?EHyQl(M}1OlQcCX>lXB*ODN003Z&P17_@)3Pi=i0wb04<W?v-u}7K
+zXmmQA+wDgE!qR9o8jr`%=ab_&uh(l?R=r;Tjiqon91I2-hIu?57~@*4h7h9uORK#=
+fQItJW-{SoTm)8|5##k|m00000NkvXXu0mjf{mKw4
+
+% import binary diff
+applying b.diff