Fix revlog-ng interaction with old-http. revlog.py wasn't trying to detect the version of a revlog file that doesn't exist on the filesystem (as is the case with old-http). Additionally, there was an off-by-one error in httprangereader.read (ranges in HTTP Range headers are inclusive), making it get more data than what was asked for. This made a struct.unpack complain that "unpack str size does not match format". Finally, with the two fixes above, test-static-http fails, since BaseHTTPServer doesn't understand ranges and returns too much data. Work around that by reading only the specified amount.

diff -r acd8075edac9 b
--- /dev/null
+++ b/b
@@ -0,0 +1,1 @@
+123
diff -r acd8075edac9 b
--- /dev/null
+++ b/b
@@ -0,0 +1,1 @@
+123
diff -r acd8075edac9 a
--- a/a
+++ b/a
@@ -0,0 +1,1 @@
+foo
diff -r acd8075edac9 b
--- /dev/null
+++ b/b
@@ -0,0 +1,1 @@
+123