Inconsistent formatting in `XStringQuality` objects

[ahl27]

XStringQuality names don't render correctly for the quality object when quality scores contain backslashes. Seems like a quirk of R interpreting the backslash and the subsequent character as a single character.

q <- PhredQuality(c("\\]^_`abcd", "\\]^_`abcde", "AAAAAAAAAA"))
names(q) <- letters[1:3]
q
## PhredQuality object of length 3:
##     width seq                                               names               
## [1]     9 \]^_`abcd                                        a
## [2]    10 \]^_`abcde                                       b
## [3]    10 AAAAAAAAAA                                        c