Allow usage of algorithm2e package (#8744)

This simple module allows users to use the algorithm2e package at all. Before, it was not possible with LyX, since this package conflicts with LyX's own algorithm support (see also #8728)

lib/Makefile.am

@@ -1890,6 +1890,7 @@ dist_layouts_DATA =\
 	layouts/agu_stdtitle.inc \
 	layouts/agums.layout \
 	layouts/aguplus.inc \
+	layouts/algorithm2e.module \
 	layouts/amsart.layout \
 	layouts/amsbook.layout \
 	layouts/amsdefs.inc \

lib/chkconfig.ltx

@@ -271,6 +271,7 @@
 \TestPackage{accents}
 \TestPackage{achicago}
 \TestPackage{algorithm}
+\TestPackage{algorithm2e}
 \TestPackage{amstext}
 \TestPackage{apacite}
 \TestPackage{apalike}

lib/doc/LaTeXConfig.lyx

@@ -1,5 +1,5 @@
 #LyX 2.1 created this file. For more info see http://www.lyx.org/
-\lyxformat 462
+\lyxformat 474
 \begin_document
 \begin_header
 \textclass article
@@ -31,6 +31,7 @@
 \use_geometry false
 \use_package amsmath 0
 \use_package amssymb 0
+\use_package cancel 0
 \use_package esint 0
 \use_package mathdots 0
 \use_package mathtools 0
@@ -39,7 +40,7 @@
 \use_package stmaryrd 0
 \use_package undertilde 0
 \cite_engine basic
-\cite_engine_type numerical
+\cite_engine_type default
 \biblio_style plain
 \use_bibtopic false
 \use_indices false
@@ -59,7 +60,7 @@
 \papercolumns 1
 \papersides 1
 \paperpagestyle plain
-\tracking_changes false
+\tracking_changes true
 \output_changes false
 \html_math_output 0
 \html_css_as_file 0
@@ -67,6 +68,7 @@
 \html_latex_start <span class='latex'>
 \html_latex_end </span>
 \author -1379302345 "Julien Rioux" jrioux@lyx.org
+\author -712698321 "Jürgen Spitzmüller" 
 \end_header
 
 \begin_body
@@ -6193,6 +6195,74 @@ index of algorithms
 \end_inset
 
  too.
+\change_inserted -712698321 1390760230
+
+\end_layout
+
+\begin_layout Subsection
+
+\change_inserted -712698321 1390760234
+algorithm2e
+\end_layout
+
+\begin_layout Description
+
+\change_inserted -712698321 1390760231
+Found: 
+\begin_inset Info
+type  "package"
+arg   "algorithm2e"
+\end_inset
+
+
+\end_layout
+
+\begin_layout Description
+
+\change_inserted -712698321 1390760405
+CTAN: 
+\family typewriter
+/macros/latex/contrib/algorithm2e/
+\end_layout
+
+\begin_layout Description
+
+\change_inserted -712698321 1390760383
+Notes: The package 
+\family sans
+algorithm2e
+\family default
+ is an alternative, somewhat more powerful way to output 
+\begin_inset Quotes eld
+\end_inset
+
+algorithm
+\begin_inset Quotes erd
+\end_inset
+
+ floats.
+ If you want to use it instead of the standard 
+\family sans
+algorithm
+\family default
+ package, select the module 
+\begin_inset Quotes eld
+\end_inset
+
+Algorithm2e
+\begin_inset Quotes erd
+\end_inset
+
+ in 
+\family sans
+Document\SpecialChar \menuseparator
+Settings\SpecialChar \ldots{}
+\SpecialChar \menuseparator
+Modules
+\family default
+.
+\change_unchanged
+
 \end_layout
 
 \begin_layout Subsection

lib/layouts/algorithm2e.module

@@ -0,0 +1,26 @@
+#\DeclareLyXModule[algorithm2e.sty]{Algorithm2e}
+#DescriptionBegin
+# Use the algorithm2e package for algorithm floats rather
+# then LyX's home-brewn algorithm floats.
+#DescriptionEnd
+#
+#Author: Jürgen Spitzmüller
+
+Format 35
+
+Requires algorithm2e
+
+Float
+	Type                  algorithm
+	GuiName               Algorithm
+	Placement             tbp
+	Extension             loa
+	NumberWithin          none
+	Style                 plain
+	ListName              "List of Algorithms"
+	IsPredefined          true
+	UsesFloatPkg          false
+	ListCommand           listofalgorithms
+	RefPrefix             alg
+End
+

src/LaTeXFeatures.cpp

@@ -740,7 +740,8 @@ char const * simplefeatures[] = {
 	"multirow",
 	"tfrupee",
 	"shapepar",
-	"rsphrase"
+	"rsphrase",
+	"algorithm2e"
 };
 
 char const * bibliofeatures[] = {