Log Message:
Updated flex to 2.6.2.

Slightly based on wip/flex by Makoto Fujiwara and Juraj Lutter.

* version 2.6.2 released 2016-10-24

** flex internals

*** a segfalt involving yyrestart(NULL) has been fixed

*** flex should now handle quoting when mixed with m4 processing correctly

*** flex handles `[[' and `]]' correctly

*** flex no longer generates non-ANSI code

*** more compilation warnings were squashed in generated scanners

*** prevented a buffer overflow that could occur when input buffers were the \ 
exact wrong size

** test suite

*** input filenames on MSWindows are now calculated correctly

*** general code cleanups in a number of tests now make the test suite compile \ 
much more cleanly

** build system

*** the xz archive has been replaced with an lzip archive

*** a new option to configure --enable-warnings to encapsulate passing
    of warning-related flags which is useful in testing flex

*** make indent now works for out of source builds

*** Portability warnings when generating Makefile.in files are now suppressed; \ 
they were just noise and the use of GNU extensions in Makefile.{am,in,} was \ 
intentional and well known.

** bugs

*** resolved gh#67

** new sv translation from the translation project

* version 2.6.1 released 2016-03-01

** flex resources

*** The flex project is now hosted at github. Consider this a "period of \ 
transition". In particular, you should start at \ 
https://github.com/westes/flex for the flex codebase, issue tracking and pull \ 
requests.

*** New releases of flex are to be found at https://github.com/westes/flex/releases.

** flex internals

*** Flex now uses more modern and more standard names for variable types. \ 
There's more work to be done on that front yet, though.

*** A number of compiler warnings have been remedied.

*** Line directives should now  work as expected and be absent when that is expected.

** test suite

*** When running the test suite, c++ files are compiled with the c++ header \ 
inside the flex distribution, rather than relying on the build system's flex \ 
header , which might not be installed yet or which might be out of date with \ 
respect to what flex tests expect.

*** Some portability fixes in the test suite such as opening files for reading \ 
in binary mode

** Building flex

*** The file src/scan.c asdistributed  with flex source is now built with the \ 
current version of flex. Occasionally this had to be done manually to pick up \ 
new flex features. It's now just a part of flex's build system.

*** The pdf version of the manual is no longer distributed with flex, although \ 
if you have the texinfo package installed, you can still build it.

*** lots of general build system cleanup

*** the build system tries a bit harder to find libtoolize and texi2dvi.

*** When help2man and texi2dvi are missing, the error messages are now much more \ 
helpful.

** bug fixes

*** resolved github issues #53, #54, #55, #61.

*** Resolved sf bugs #128, #129, #155, #160, #184, #187, #195.