Make LintChecker().lint_text('<code>') possible.

Made LintChecker()'s "view" and lint_text's "filename" arguments optional. Filename will default to <stdin> like Python does when you pipe to it. Also return found errors from lint_text as a convenience.

Tools/capp_lint/capp_lint

@@ -266,7 +266,7 @@ class LintChecker(object):
     TEXT_ERROR_SINGLE_FILE_TEMPLATE = Template(u'$lineNum: $message.\n+$line\n')
     TEXT_ERROR_MULTI_FILE_TEMPLATE = Template(u'$filename:$lineNum: $message.\n+$line\n')
 
-    def __init__(self, view, basedir='', var_declarations=VAR_DECLARATIONS_SINGLE, verbose=False):
+    def __init__(self, view=None, basedir='', var_declarations=VAR_DECLARATIONS_SINGLE, verbose=False):
         self.view = view
         self.basedir = unicode(basedir, 'utf-8')
         self.errors = []
@@ -747,7 +747,7 @@ class LintChecker(object):
                     print u'EOF\n'
                 pass
 
-    def lint_text(self, text, filename):
+    def lint_text(self, text, filename="<stdin>"):
         self.filename = filename
         self.filesToCheck = []
 
@@ -759,6 +759,8 @@ class LintChecker(object):
                 print u'EOF\n'
             pass
 
+        return self.errors
+
     def count_files_checked(self):
         return len(self.filesToCheck)