acinclude.m4: Fix "sparse", via detection of GNU make "if" directive.

Make treats tabs very differently from spaces at the beginning of a line,
so this test must use a tab instead of a space.  This partially reverts
commit a0903134d2d60 (acinclude.m4: Expand tabs).

Without this commit, the build system never enables checking with sparse
because it never detects that GNU make "if" works.

CC: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: Ben Pfaff <blp@nicira.com>
meta-flow: Simplify handling of a variable number of registers.

At the time that Open vSwitch implemented registers, there was a high cost
to adding additional fields, so I wrote the code so that the number of
registers could be reduced at compile time.  Now, fields are cheaper
(though not free) and in the meantime I have never heard of anyone reducing
the number of registers.  Since I intend to add more code that would
require awkward "#if"s like this, I think that this is a good time to
simplify it by requiring FLOW_N_REGS to be fixed.  This commit does that.

Signed-off-by: Ben Pfaff <blp@nicira.com>
classifier: Remove assumption that there are 64 or fewer fields.

An upcoming commit will increase the number of fields beyond 64.

Signed-off-by: Ben Pfaff <blp@nicira.com>
meta-flow: Add 64-bit registers.

These 64-bit registers are intended to conform with the OpenFlow 1.5
draft specification.

EXT-244.
Signed-off-by: Ben Pfaff <blp@nicira.com>
ofp-actions: Simplify ofpact_to_openflow12().

This function had two levels of nested switch statements, but the outer one
seems to be more or less superfluous.  This commit removes a lot more code
than it adds.

(This commit is much smaller ignoring whitespace-only changes.)

Signed-off-by: Ben Pfaff <blp@nicira.com>
ofp-actions: Refactor converting ofpacts to OpenFlow 1.1 and 1.2 actions.

As we continue to add support for newer versions of OpenFlow actions, it
seems crude to add layers of wrappers around ofpact_to_openflow11().  This
commit squashes the two existing layers together.

This prepares to add the new OpenFlow 1.5 "copy-field" action.

Signed-off-by: Ben Pfaff <blp@nicira.com>
ofp-actions: Add OpenFlow 1.5 "copy-field" action.

EXT-320.
Signed-off-by: Ben Pfaff <blp@nicira.com>