Handle old IE JavaScript errors

[G0dwin]

We get reports for JS fatals for IE 8 and 9 due to the use of unsupported calls like querySelector. For the most part these errors are handled so that the error doesn't affect the ability to use the site, but the errors are still thrown and we get frequent error report emails about them.

The easiest thing to do would be to do a simple check and not execute certain portions of the code if objects don't exist.

[G0dwin]

TypeError: Cannot find function addEventListener in object [object HTMLDivElement]. (script in https://en.bikebike.org/ from (160, 9) to (164, 10)|_|/html/body/script#162)
  at https://en.bikebike.org/:162:undefined

Object doesn't support property or method 'querySelector'
  at https://en.bikebike.org/user/confirm/8a7c1ff80b152c1327acc41c8a9bd979cd37e1e5040551bfd04c7d136a39d703/:147:undefined

NS_ERROR_FAILURE: @https://en.bikebike.org/assets/quill-dd692e038768cf33a1cb4026fab85175afbbbc7e0ea6a0c5fcbf101f5fa4515a.js:2:6430

Unable to get value of the property 'add': object is null or undefined
  at https://en.bikebike.org/user/confirm/bc7f05147ed73ff1b63a252abfb9aabf53ba81dffc0d458351b90b013873f696/:148:undefined