1.0.8.15: making SBCL sources Git more friendly

* Git for SBCL Hackers guide.

 * If branch-version.lisp-expr exists, it's value is concatenated
   after the contents of version.lisp-expr, separated out by ".".

   Doing this allows reduces spurious conflicts on branches: otherwise
   a branch announcing it's name in version.lisp-expr is going to
   conflict at every turn, which prevents automatic rebasing and
   merging from doing TRT.

 * Added .gitignore

.gitignore

@@ -0,0 +1,28 @@
+*.d
+*.o
+*.fasl
+*.lisp-temp
+*.tmp
+*~
+output
+obj
+local-target-features.lisp-expr
+customize-target-features.lisp
+src/assembly/target
+src/compiler/assembly
+src/compiler/target
+src/runtime/Config
+src/runtime/genesis
+src/runtime/ldso-stubs.S
+src/runtime/sbcl
+src/runtime/sbcl.h
+src/runtime/sbcl.nm
+src/runtime/target-arch-os.h
+src/runtime/target-arch.h
+src/runtime/target-lispregs.h
+src/runtime/target-os.h
+tools-for-build/grovel-headers
+contrib/*/test-passed
+contrib/*/foo.c
+contrib/*/a.out
+contrib/sb-cover/test-output

src/code/misc.lisp

@@ -16,4 +16,8 @@
   "SBCL")
 
 (defun sb!xc:lisp-implementation-version ()
-  #.(sb-cold:read-from-file "version.lisp-expr"))
+  #.(format nil "~A~@[.~A~]"
+            (sb-cold:read-from-file "version.lisp-expr")
+            (let ((pathname "branch-version.lisp-expr"))
+              (when (probe-file pathname)
+                (sb-cold:read-from-file pathname)))))

version.lisp-expr

@@ -17,4 +17,4 @@
 ;;; checkins which aren't released. (And occasionally for internal
 ;;; versions, especially for internal versions off the main CVS
 ;;; branch, it gets hairier, e.g. "0.pre7.14.flaky4.13".)
-"1.0.8.14"
+"1.0.8.15"