gitignore: Add some generated files in the guest subdirectory

Signed-off-by: Diego Biurrun <diego@biurrun.de>
guest: Build Linux tools non-recursively

This is more correct and simplifies the Makefile structure.

Signed-off-by: Diego Biurrun <diego@biurrun.de>
s2e.h: Refactor repetitive inline assembly statements for S2E opcodes

Signed-off-by: Diego Biurrun <diego@biurrun.de>
misc typo fixes

Signed-off-by: Diego Biurrun <diego@biurrun.de>
docs: contribute: Adjust small grammar error.
docs: Fix errors in example plugin code
qemu: Set PKGVERSION to differentiate S2E qemu builds from vanilla qemu.

Originally fixed by Diego Biurrun

Signed-off-by: Vitaly Chipounov <vitaly.chipounov@epfl.ch>
build: added missing EXTRA_QEMU_FLAGS to asan build

Signed-off-by: Vitaly Chipounov <vitaly.chipounov@epfl.ch>
build: added EXTRA_QEMU_FLAGS explanation to the main Makefile

Signed-off-by: Vitaly Chipounov <vitaly.chipounov@epfl.ch>