Code Cleanup

- Removed obsolete grammar file.
- Cleaned up .gitignore.

src/.gitignore

@@ -2,5 +2,4 @@
 Makefile.in
 *_test
 args
-parser
 calc

src/grammar.bnf

@@ -1,84 +0,0 @@
-# The command line needs to obey a grammar.  It is against this grammar that
-# bugs will be identified.
-# 
-# Conventions:
-#   - Literals are always double-quoted.
-#   - "*", "+" and "?" suffixes have POSIX semantics.
-#   - Low-level primitives are in <brackets>.
-#   - @name for entity lists such as custom report names.
-# 
-# The general form of commands is:
-#   task [ all-commands ]
-#
-
-  grammar         ::= all-commands?
-                    ;
-
-  all-commands    ::= report-command
-#                    | read-command
-                    | write-command
-#                    | special-command
-                    ;
-
-  report-command  ::= filter @report ;
-#  read-command    ::= filter @readcmd ;
-  write-command   ::= filter @writecmd modifiers ;
-#  special-command ::= ;
-
-  filter          ::= expression? ;
-
-  expression      ::= term "and" expression
-                    | term "or"  expression
-                    | term
-                    ;
-
-  term            ::= ;
-
-  modifiers       ::= ;
-
-# Low-level:
-
-#  dom             ::= context-value
-#                    | system-value
-#                    | rc-value
-#                    | task-value
-#                    ;
-
-#  context-value   ::= "context.program"
-#                    | "context.args"
-#                    | "context.width"
-#                    | "context.height"
-#                    ;
-
-#  system-value    ::= "system.version"
-#                    | "system.os"
-#                    ;
-
-#  rc-value        ::= /rc\.[a-zA-Z.]+/
-#                    ;
-
-#  task-value      ::= <id> "." @attribute
-#                    | <uuid> "." @attribute
-#                    ;
-
-#  literal         ::= <string>
-#                    | <numeric>
-#                    | <date>
-#                    | <duration>
-#                    ;
-
-# Supported primitives:
-#
-#  <id>
-#  <uuid>
-#  <override>    "rc." name "=" string
-#  <string>      " ... "
-#  <numeric>
-#  <date>        ISO-8601 date
-#  <duration>    ISO-8601 duration
-#  @command      all commands
-#  @report       all custom reports
-#  @attribute    all attributes, UDAs
-#  @readcmd      all read-only commands
-#  @writecmd     all write commands
-