ToruNiina/toml11: version 3.3.1

Fixed

• Fix clang -Wrange-loop-analysis. (#98) (@jwillikers )
  • Avoid the unnecessary copy of strings.
• Fix clang -Wundef. (#99) (@jwillikers )
  • Check environment-specific macro definition before using it
• Use cache variables in CMakeLists (#101 ) (@jwillikers )
• Fix edge cases around TOML strings.
  • Recently TOML spec clarified behaviors in some edge cases around strings.
  • toml11 now works with all the following examples listed in the official spec.
  • toml11 serializer output becomes cleaner in those edge-cases.

# The following examples are copied from the official TOML spec.

str4 = """Here are two quotation marks: "". Simple enough."""
# str5 = """Here are three quotation marks: """."""  # INVALID
str5 = """Here are three quotation marks: ""\"."""
str6 = """Here are fifteen quotation marks: ""\"""\"""\"""\"""\"."""

# "This," she said, "is just a pointless statement."
str7 = """"This," she said, "is just a pointless statement.""""

quot15 = '''Here are fifteen quotation marks: """""""""""""""'''

# apos15 = '''Here are fifteen apostrophes: ''''''''''''''''''  # INVALID
apos15 = "Here are fifteen apostrophes: '''''''''''''''"

# 'That's still pointless', she said.
str = ''''That's still pointless', she said.'''