Add = and " to escapable character list
Fix incorrect escaping logic in find_emph_char
Better logic to handle backslashes

is_escaped actually counts backslashes instead of looking back one
character to determine whether a character is escaped. This handles
inputs like *Foo\\* correctly (as `<p><em>Foo\<em></p>`; would be
`<p>Foo\*</p>` previously).
Add test cases for escape characters
Fix incorrect file name
Fix escaping in char_link and add tests

Same logic as 2301e4c
Fix superscript group escaping
Make return statement of is_escaped more succinct
Need to handle backticks in find_emph_char
Add comments
Reusing find_emph_char logic in char_superscript
Make comments in char_emphasis up-to-date
Input of find_emph_char should INCLUDE opening

This fixes super^(`)`)
Use find_emph_char for table column parsing

Fix #77
find_emph_char should starts from the beginning

This fixes bugs for edge cases of pattern:

    opening  backtick  ending  [any]  backtick  [any]  ending

Examples: *`**`* and __`__`__

Range handling in 48a19b3 and e7bcbe3 is also changed to match the
correct behavior.
Use find_emph_char to find delims in char_quote
Merge pull request #97 from uranusjr/fix_89-markup-escape

Fix markup characters escaping