Add .gitignore

Also need to add other generated files that should not be committed, namely autoconf.


Former-commit-id: d589a3c8b6204a8d5cb760c96a196349c0761732

.gitignore

+# http://www.gnu.org/software/automake
+
+Makefile.in
+
+# http://www.gnu.org/software/autoconf
+
+/autom4te.cache
+/aclocal.m4
+/compile
+/configure
+/depcomp
+/install-sh
+/missing
+/stamp-h1
+# Object files
+*.o
+*.ko
+*.obj
+*.elf
+
+# Precompiled Headers
+*.gch
+*.pch
+
+# Libraries
+*.lib
+*.a
+*.la
+*.lo
+*.lai
+
+# Shared objects (inc. Windows DLLs)
+*.dll
+*.so
+*.so.*
+*.dylib
+
+# Executables
+*.exe
+*.out
+*.app
+*.i*86
+*.x86_64
+*.hex
+
+## Core latex/pdflatex auxiliary files:
+*.aux
+*.lof
+*.log
+*.lot
+*.fls
+*.out
+*.toc
+
+## Intermediate documents:
+*.dvi
+*-converted-to.*
+# these rules might exclude image files for figures etc.
+# *.ps
+# *.eps
+# *.pdf
+
+## Bibliography auxiliary files (bibtex/biblatex/biber):
+*.bbl
+*.bcf
+*.blg
+*-blx.aux
+*-blx.bib
+*.brf
+*.run.xml
+
+## Build tool auxiliary files:
+*.fdb_latexmk
+*.synctex
+*.synctex.gz
+*.synctex.gz(busy)
+*.pdfsync
+
+## Auxiliary and intermediate files from other packages:
+
+# algorithms
+*.alg
+*.loa
+
+# achemso
+acs-*.bib
+
+# amsthm
+*.thm
+
+# beamer
+*.nav
+*.snm
+*.vrb
+
+# glossaries
+*.acn
+*.acr
+*.glg
+*.glo
+*.gls
+
+# hyperref
+*.brf
+
+# knitr
+*-concordance.tex
+*.tikz
+*-tikzDictionary
+
+# listings
+*.lol
+
+# makeidx
+*.idx
+*.ilg
+*.ind
+*.ist
+
+# minitoc
+*.maf
+*.mtc
+*.mtc0
+
+# minted
+_minted*
+*.pyg
+
+# morewrites
+*.mw
+
+# nomencl
+*.nlo
+
+# sagetex
+*.sagetex.sage
+*.sagetex.py
+*.sagetex.scmd
+
+# sympy
+*.sout
+*.sympy
+sympy-plots-for-*.tex/
+
+# todonotes
+*.tdo
+
+# xindy
+*.xdy