Check license compliance

[kingjon3377]

The licenses of some of our dependencies, particularly non-direct dependencies, require acknowledgement in user-facing text (which in our case is the README and the About dialog). I need to go through each of them to make sure this project is in compliance, and if not add the necessary acknowledgement.

I have a WIP branch for this locally, but don't intend to push it until it's done, and it's currently on hold.

Something like FOSSology, ScanCode, or ORT may help here.

Before I list the code dependencies:

• Icon (and other image, if any) licenses

Here's a full list of (mostly indirect) dependencies as of64cfefea36b33161ea51bf19c11c8007780ffb76, as provided by ceylon info:

• ceylon.buffer/1.3.3
• ceylon.collection/1.3.3: Apache-2.0 (need to check for "notices")
• ceylon.dbc/1.3.3: Apache-2.0 (need to check for "notices")
• ceylon.decimal/1.3.3
• ceylon.file/1.3.3
• ceylon.interop.java/1.3.3
• ceylon.language/1.3.3: Apache-2.0 (need to check for "notices")
• ceylon.logging/1.3.3
• ceylon.numeric/1.3.3
• ceylon.random/1.3.3: Apache-2.0 (need to check for "notices")
• ceylon.regex/1.3.3: Apache-2.0 (need to check for "notices")
• ceylon.runtime/1.3.3
• ceylon.test/1.3.3
• ceylon.time/1.3.3
• ceylon.transaction/1.3.3: Apache-2.0 (need to check for "notices")
• ceylon.whole/1.3.3
• com.github.rjeschke.txtmark/0.13
• com.google.code.findbugs:annotations/3.0.1
• com.google.code.findbugs:jsr305/3.0.1: Apache-2.0 (need to check for "notices")
• com.massisframework:orange-extensions/1.3.1: "BSD" (need to check which)
• com.pump/0.0
• com.redhat.ceylon.cli/1.3.3
• com.redhat.ceylon.common/1.3.3
• com.redhat.ceylon.compiler.java/1.3.3
• com.redhat.ceylon.compiler.js/1.3.3
• com.redhat.ceylon.langtools.classfile/1.3.3
• com.redhat.ceylon.model/1.3.3
• com.redhat.ceylon.module-loader/1.3.3
• com.redhat.ceylon.module-resolver/1.3.3
• com.redhat.ceylon.module-resolver-javascript/1.3.3
• com.redhat.ceylon.tool.provider/1.3.3
• com.redhat.ceylon.typechecker/1.3.3
• com.vasileff.ceylon.structures/1.1.3
• java.base: 7, 8
• java.compiler/7
• java.desktop: 7, 8
• java.instrument/7
• java.jdbc/7
• java.logging/7
• java.management/7
• java.prefs/7
• java.tls/7
• javax.jaxws/7
• javax.json:javax.json-api/1.0
• javax.naming/7
• javax.script/7
• javax.servlet:javax.servlet-api/4.0.0: CDDL + GPL-2 (w/ Classpath exception)
• javax.transaction/7
• javax.transaction.api/1.2.0.Final-1
• javax.xml: 7, 8
• net.jcip:jcip-annotations/1.0
• net.minidev.json-smart/1.3.1
• oracle.jdk.base/7
• org.antlr.runtime/3.5.2
• org.apache.commons:commons-lang3/3.7
• org.apache.commons:commons-text/1.4
• org.cactoos:cactoos/0.42: MIT
• org.jboss.common-core/2.2.22.GA
• org.jboss.jboss-transaction-spi/7.3.1.Final-1
• org.jboss.jnpserver/5.0.3.GA
• org.jboss.logging: 3.1.3.GA, 3.3.0.Final
• org.jboss.logmanager/2.0.3.Final
• org.jboss.modules/1.4.4.Final
• org.jboss.narayana.jta/5.2.7.Final-1
• org.projectlombok:lombok/1.16.10: MIT
• org.roaringbitmap:RoaringBitmap/0.9.0: Apache-2.0 (need to check for "notices")
• org.roaringbitmap:shims/0.9.0: Apache-2.0 (need to check for "notices")
• org.takes:takes/1.19: MIT
• org.xerial:sqlite-jdbc/3.31.1: Apache-2.0 (need to check for "notices")
• xml-apis:xml-apis/1.4.01: Apache-2.0 (need to check for "notices")