GitRepository: Add an "all branches" option in branches list

This is probably the most common non-branch GitX option, so
let's add it by default

PBGitRepository.m

@@ -231,6 +231,9 @@ static NSString* gitPath;
 	}
 
 	self.refs = refs;
+
+	// Add an "All branches" option in the branches list
+	[self addBranch:[PBGitRevSpecifier allBranchesRevSpec]];
 	return ret;
 }
 

PBGitRevSpecifier.h

@@ -23,6 +23,9 @@
 - (BOOL) hasLeftRight;
 
 - (BOOL) isEqualTo: (PBGitRevSpecifier*) other;
-@property(readonly) NSString* description;
+
++ (PBGitRevSpecifier *)allBranchesRevSpec;
+
+@property(copy) NSString* description;
 @property(readonly) NSArray* parameters;
 @end

PBGitRevSpecifier.m

@@ -11,7 +11,7 @@
 
 @implementation PBGitRevSpecifier
 
-@synthesize parameters;
+@synthesize parameters, description;
 
 - (id) initWithParameters:(NSArray*) params
 {
@@ -27,6 +27,13 @@
 	return self;
 }
 
++ (PBGitRevSpecifier *)allBranchesRevSpec
+{
+	id revspec = [[PBGitRevSpecifier alloc] initWithParameters:[NSArray arrayWithObject:@"--all"]];
+	[revspec setDescription:@"All branches"];
+	return revspec;
+}
+	
 - (BOOL) isSimpleRef
 {
 	return ([parameters count] == 1 && ![[parameters objectAtIndex:0] hasPrefix:@"-"]);