message: add \bigl( and other commands.
diff: "snippet":"left\\{${1}\\right\\\\}",
  "detail":"\\left\\{ ... \\right\\}"
  },
  + "biglrparen":{
  + "command":"bigl(",
  + "snippet":"bigl(${1}\\bigr)",
  + "detail":"\\bigl( ... \\bigr)"
  + },
  + "biglrbrack":{
  + "command":"bigl[",
  + "snippet":"bigl[${1}\\bigr]",
  + "detail":"\\bigl[ ... \\bigr]"
  + },
  + "biglrcurly":{
  + "command":"bigl\\{",
  + "snippet":"bigl\\{${1}\\bigr\\\\}",
  + "detail":"\\bigl\\{ ... \\bigr\\}"
  + },
  + "Biglrparen":{
  + "command":"Bigl(",
  + "snippet":"Bigl(${1}\\Bigr)",
  + "detail":"\\Bigl( ... \\Bigr)"
  + },
  + "Biglrbrack":{
  + "command":"Bigl[",
  + "snippet":"Bigl[${1}\\Bigr]",
  + "detail":"\\Bigl[ ... \\Bigr]"
  + },
  + "Biglrcurly":{
  + "command":"Bigl\\{",
  + "snippet":"Bigl\\{${1}\\Bigr\\\\}",
  + "detail":"\\Bigl\\{ ... \\Bigr\\}"
  + },
  + "bigglrparen":{
  + "command":"biggl(",
  + "snippet":"biggl(${1}\\biggr)",
  + "detail":"\\biggl( ... \\biggr)"
  + },
  + "bigglrbrack":{
  + "command":"biggl[",
  + "snippet":"biggl[${1}\\biggr]",
  + "detail":"\\biggl[ ... \\biggr]"
  + },
  + "bigglrcurly":{
  + "command":"biggl\\{",
  + "snippet":"biggl\\{${1}\\biggr\\\\}",
  + "detail":"\\biggl\\{ ... \\biggr\\}"
  + },
  + "Bigglrparen":{
  + "command":"Biggl(",
  + "snippet":"Biggl(${1}\\Biggr)",
  + "detail":"\\Biggl( ... \\Biggr)"
  + },
  + "Bigglrbrack":{
  + "command":"Biggl[",
  + "snippet":"Biggl[${1}\\Biggr]",
  + "detail":"\\Biggl[ ... \\Biggr]"
  + },
  + "Bigglrcurly":{
  + "command":"Biggl\\{",
  + "snippet":"Biggl\\{${1}\\Biggr\\\\}",
  + "detail":"\\Biggl\\{ ... \\Biggr\\}"
  + },
  "frame":{
  "command":"frame",
  "snippet":"begin{frame}\n\t\\frametitle{${1:<title>}}\n\n\t$0\n\n\\end{frame}",
  