Fix "this decimal constant is unsigned only in ISO C90".

name_sentry dtor results in multiple symbol definition errors in MSVC6.

Since they don't contribute to the resulting value just skip them before
parsing. This matches the behavior of strtol/strtoll and results in more
intuitive behavior.

Node type enum is not used as an array index anywhere else; the code is not
very readable and the value of this "optimization" is questionable.

The conditions are arranged so that in all normal cases the first comparison
returns true anyway.

The minneg argument is supposed to be the absolute value of the minimum negative
representable number. In case of two-complement arithmetic, it's the same as the
value itself but it's better to be explicit and negate the argument.

Share the implementation for different encodings. We still need two functions
because endian_swap on uint8_t is ambiguous...

This avoids linker warning when building the final executable and we don't
have to package the .PDB file.

Move pugixml project file for VS2015 to scripts/ and unify the output file
structure similar to old VS201x projects. Remove test projects and solution
since they are not required for building.

Provide more accurate information in the package script and handle build
errors during package construction properly.

Instead of functions with different names (e.g. decode_utf8_block), split
utf_decoder class into multiple classes with ::process static function.

This makes it easier to share code for decoding different encodings.

This does not affect correctness but makes code more uniform.

Make sure the looping structure is the same as in decode_utf8_block.

Instead of calling xml_document public functions just call implementation of
load_buffer_inplace_own. This makes it so we only call reset() once during
load_file/load.

This makes sure we get linking errors whenever a symbol is not marked as inline
in header-only mode.

Fixed missing PUGI__FN

We now make sure that in CMake builds we have long long support. This requires
CMake 3.1 for target_compile_features.

Fixes #53 (as long as packages use this CMake script... most of them do)

This matches the format strtol supports.

Add OSX to Travis CI config

We don't need to test gcc on OSX

These tests are only testing attribute as_int in hopes that xml_text uses the
same underlying implementation (which it does).